大学物理波动光学英语实验报告、论文
大学物理论文(波动与光学)
波动与光学（感谢老师这学期为我们的付出，敬佩老师的教学态度，经此我们学到了很多东西，真的很感谢）对于光的认识简史:光是人类和生物生存和发展所必需的，人们对于它的认识却经历了漫长而曲折的过程。
最早的人们认为光是由微粒构成的，牛顿就是微粒说的创始人和坚持者，而惠更斯明确的提出了光是一种波，直至19世纪托马斯—-菲涅耳从实验和理论上建立了光的波动理论。
但他们的认识持有机械论的观点。
19世纪中叶光的电磁理论的建立使人们对于光的认识更近一步，但关于介质的问题仍是矛盾重重，有待解决。
终于于19世纪末迈克尔逊实验及爱因斯坦的相对论得出结论：光是一种电磁波，它的传播不需要任何介质。
首先我们从简单的波动与振动讲起，这是光的波动说的理论基石。
关于振动的理论描述我们有它的简谐振动函数x=Acos(ωt+φ) A Φω是描述简谐运动的三个特征量，通过微分关系我们可以分别得到速度与加速度的公式。
由于简谐运动于匀速圆周运动有许多相似之处，所以在许多方面我们应用参考圆来研究他们的运动。
由简谐运动的动力学方程得k=mω2从这里我们可以对简谐运动下一个动力学定义：质点在与平衡位置成正比而反向的合力的作用下的运动叫简谐运动，由此还可以推出T A 的公式，对于简谐振动的能量我们经过一系列的微分与动力学方程推导我们得到机械能=势能与动能之和而他们的平均值各占一半。
而实际问题中常会遇到几个简谐运动的合成。
我们讨论同意直线相同频率的简谐运动的合成。
经过矢量图法我们可以推得A的合成与φ的函数关系公式。
波动。
一定扰动的传播称为波动。
再此主要研究机械波的一些相关性质的理论。
如声波，地震波，水波等。
虽然各类波的性质不同但他们在形式上由许多相同的特征规律。
我们所讲的简谐波的传播是需要介质的，他的传播形式都要经过介质的传播，这一点是不同于光的。
描述波的运动需要波函数，由于简谐波上的任意质元都在做简谐运动因而简谐波是有周期的，一个周期所传播的距离称为波长λ=uT波形曲线可以详细描述波的运动。
最新物理实验报告(英文)
最新物理实验报告(英文)Abstract:This report presents the findings of a recent physics experiment conducted to investigate the effects of quantum entanglement on particle behavior at the subatomic level. Utilizing a sophisticated setup involving photon detectors and a vacuum chamber, the experiment aimed to quantify the degree of correlation between entangled particles and to test the limits of nonlocal communication.Introduction:Quantum entanglement is a phenomenon that lies at the heart of quantum physics, where the quantum states of two or more particles become interlinked such that the state of one particle instantaneously influences the state of the other, regardless of the distance separating them. This experiment was designed to further our understanding of this phenomenon and its implications for the fundamental principles of physics.Methods:The experiment was carried out in a controlled environment to minimize external interference. A pair of photons was generated and entangled using a nonlinear crystal. The photons were then separated and sent to two distinct detection stations. The detection process was synchronized, and the data collected included the time, position, and polarization state of each photon.Results:The results indicated a high degree of correlation between the entangled photons. Despite being separated by a significant distance, the photons exhibited a consistent pattern in their polarization states, suggesting a strong entanglement effect. The data also showed that the collapse of the quantum state upon measurement occurred simultaneously for both particles, supporting the theory of nonlocality.Discussion:The findings of this experiment contribute to the ongoing debate about the nature of quantum entanglement and its potential applications. The consistent correlations observed between the entangled particles provide strong evidence for the nonlocal properties of quantum mechanics. This has implications for the development of quantum computing and secure communication technologies.Conclusion:The experiment has successfully demonstrated the robustness of quantum entanglement and its potential for practical applications. Further research is needed to explore the broader implications of these findings and to refine the experimental techniques for probing the quantum realm.References:[1] Einstein, A., Podolsky, B., & Rosen, N. (1935). Can Quantum-Mechanical Description of Physical Reality Be Considered Complete? Physical Review, 47(8), 777-780.[2] Bell, J. S. (1964). On the Einstein Podolsky RosenParadox. Physics, 1(3), 195-200.[3] Aspect, A., Grangier, P., & Roger, G. (1982). Experimental Tests of Realistic Local Theories via Bell's Theorem. Physical Review Letters, 49(2), 91-94.。
大学物理实验报告 英文版
大学物理实验报告Ferroelectric Control of Spin PolarizationABSTRACTA current drawback of spintronics is the large power that is usually required for magnetic writing, in contrast with nanoelectronics, which relies on “zero-current,” gate-controlled operations. Efforts have been made to control the spin-relaxation rate, the Curie temperature, or the magnetic anisotropy with a gate voltage, but these effects are usually small and volatile. We used ferroelectric tunnel junctions with ferromagnetic electrodes to demonstrate local, large, and nonvolatile control of carrier spin polarization by electrically switching ferroelectric polarization. Our results represent a giant type of interfacial magnetoelectric coupling and suggest a low-power approach for spin-based information control.Controlling the spin degree of freedom by purely electrical means is currently an important challenge in spintronics (1, 2). Approaches based on spin-transfer torque (3) have proven very successful in controlling the direction of magnetization in a ferromagnetic layer, but they require the injection of high current densities. An ideal solution would rely on the application of an electric field across an insulator, as in existing nanoelectronics. Early experiments have demonstrated the volatile modulation of spin-based properties with a gate voltage applied through a dielectric. Notable examples include the gate control of the spin-orbit interaction in III-V quantum wells (4), the Curie temperature T C (5), or the magnetic anisotropy (6) in magnetic semiconductors with carrier-mediated exchange interactions; for example, (Ga,Mn)As or (In,Mn)As. Electric field–induced modifications of magnetic anisotropy at room temperature have also been reported recently in ultrathin Fe-based layers (7, 8).A nonvolatile extension of this approach involves replacing the gate dielectric by a ferroelectric and taking advantage of the hysteretic response of its order parameter (polarization) with an electric field. When combined with (Ga,Mn)As channels, forinstance, a remanent control of T C over a few kelvin was achieved through polarization-driven charge depletion/accumulation (9, 10), and the magnetic anisotropy was modified by the coupling of piezoelectricity and magnetostriction (11, 12). Indications of an electrical control of magnetization have also been provided in magnetoelectric heterostructures at room temperature (13–17).Recently, several theoretical studies have predicted that large variations of magnetic properties may occur at interfaces between ferroelectrics and high-T C ferromagnets such as Fe (18–20), Co2MnSi (21), or Fe3O4 (22). Changing the direction of the ferroelectric polarization has been predicted to influence not only the interfacial anisotropy and magnetization, but also the spin polarization. Spin polarization [i.e., the normalized difference in the density of states (DOS) of majority and minority spin carriers at the Fermi level (E F)] is typically the key parameter controlling the response of spintronics systems, epitomized by magnetic tunnel junctions in which the tunnel magnetoresistance (TMR) is related to the electrode spin polarization by the Jullière formula (23). These predictions suggest that the nonvolatile character of ferroelectrics at the heart of ferroelectric random access memory technology (24) may be exploited in spintronics devices such as magnetic random access memories or spin field-effect transistors (2). However, the nonvolatile electrical control of spin polarization has not yet been demonstrated.We address this issue experimentally by probing the spin polarization of electrons tunneling from an Fe electrode through ultrathin ferroelectric BaTiO3 (BTO) tunnel barriers (Fig. 1A). The BTO polarization can be electrically switched to point toward oraway from the Fe electrode. We used a half-metallic La0.67Sr0.33MnO3(LSMO) (25) bottom electrode as a spin detector in these artificial multiferroic tunnel junctions (26, 27). Magnetotransport experiments provide evidence for a large and reversible dependence of the TMR on ferroelectric polarization direction.Fig. 1(A) Sketch of the nanojunction defined by electrically controlled nanoindentation. A thin resist is spin-coated on the BTO(1 nm)/LSMO(30 nm) bilayer. The nanoindentation is performed with a conductive-tip atomic force microscope, and the resultingnano-hole is filled by sputter-depositing Au/CoO/Co/Fe. (B) (Top) PFM phase image of a BTO(1 nm)/LSMO(30 nm) bilayer after poling the BTO along 1-by-4–μm stripes with either a negative or positive (tip-LSMO) voltage. (Bottom) CTAFM image of an unpoled area of a BTO(1 nm)/LSMO(30 nm) bilayer. Ω, ohms. (C) X-ray absorption spectra collected at room temperature close to the Fe L3,2 (top), Ba M5,4 (middle), and TiL3,2 (bottom) edges on an AlO x(1.5 nm)/Al(1.5 nm)/Fe(2 nm)/BTO(1 nm)/LSMO(30 nm)//NGO(001) heterostructure. (D) HRTEM and (E) HAADF images of the Fe/BTO interface in a Ta(5 nm)/Fe(18 nm)/BTO(50 nm)/LSMO(30 nm)//NGO(001) heterostructure. The white arrowheads in (D) indicate the lattice fringes of {011} planes in the iron layer. [110] and [001] indicate pseudotetragonal crystallographic axes of the BTO perovskite.The tunnel junctions that we used in this study are based on BTO(1 nm)/LSMO(30 nm) bilayers grown epitaxially onto (001)-oriented NdGaO3 (NGO) single-crystal substrates (28). The large (~180°) and stable piezoresponse force microscopy (PFM) phase contrast (28) between negatively and positively poled areas (Fig. 1B, top) indicates that the ultrathin BTO films are ferroelectric at room temperature (29). The persistence of ferroelectricity for such ultrathin films of BTO arises from the large lattice mismatch with the NGO substrate (–3.2%), which is expected to dramatically enhance ferroelectric properties in this highly strained BTO (30). The local topographical and transport properties of the BTO(1 nm)/LSMO(30 nm) bilayers were characterized by conductive-tip atomic force microscopy (CTAFM) (28). The surface is very smooth with terraces separated by one-unit-cell–high steps, visible in both the topography (29) and resistance mappings (Fig. 1B, bottom). No anomalies in the CTAFM data were observed over lateral distances on the micrometer scale.We defined tunnel junctions from these bilayers by a lithographic technique based on CTAFM (28, 31). Top electrical contacts of diameter ~10 to 30 nm can be patterned by this nanofabrication process. The subsequent sputter deposition of a 5-nm-thick Fe layer, capped by a Au(100 nm)/CoO(3.5 nm)/Co(11.5 nm) stack to increase coercivity, defined a set of nanojunctions (Fig. 1A). The same Au/CoO/Co/Fe stack was deposited on another BTO(1 nm)/LSMO(30 nm) sample for magnetic measurements. Additionally, a Ta(5 nm)/Fe(18 nm)/BTO(50 nm)/LSMO(30 nm) sample and a AlO x(1.5 nm)/Al(1.5nm)/Fe(2 nm)/BTO(1 nm)/LSMO(30 nm) sample were realized for structural and spectroscopic characterizations.We used both a conventional high-resolution transmission electron microscope (HRTEM) and the NION UltraSTEM 100 scanning transmission electron microscope (STEM) to investigate the Fe/BTO interface properties of the Ta/Fe/BTO/LSMO sample. The epitaxial growth of the BTO/LSMO bilayer on the NGO substrate was confirmed by HRTEM and high-resolution STEM images. The low-resolution, high-angle annular dark field (HAADF) image of the entire heterostructure shows the sharpness of theLSMO/BTO interface over the studied area (Fig. 1E, top). Figure 1D reveals a smooth interface between the BTO and the Fe layers. Whereas the BTO film is epitaxially grown on top of LSMO, the Fe layer consists of textured nanocrystallites. From the in-plane (a) and out-of-plane (c) lattice parameters in the tetragonal BTO layer, we infer that c/a = 1.016 ± 0.008, in good agreement with the value of 1.013 found with the use of x-ray diffraction (29). The interplanar distances for selected crystallites in the Fe layer [i.e.,~2.03 Å (Fig. 1D, white arrowheads)] are consistent with the {011} planes ofbody-centered cubic (bcc) Fe.We investigated the BTO/Fe interface region more closely in the HAADF mode of the STEM (Fig. 1E, bottom). On the BTO side, the atomically resolved HAADF image allows the distinction of atomic columns where the perovskite A-site atoms (Ba) appear as brighter spots. Lattice fringes with the characteristic {100} interplanar distances of bcc Fe (~2.86 Å) can be distinguished on the opposite side. Subtle structural, chemical, and/or electronic modifications may be expected to occur at the interfacial boundarybetween the BTO perovskite-type structure and the Fe layer. These effects may lead to interdiffusion of Fe, Ba, and O atoms over less than 1 nm, or the local modification of the Fe DOS close to E F, consistent with ab initio calculations of the BTO/Fe interface (18–20).To characterize the oxidation state of Fe, we performed x-ray absorption spectroscopy (XAS) measurements on a AlO x(1.5 nm)/Al(1.5 nm)/Fe(2 nm)/BTO(1 nm)/LSMO(30 nm) sample (28). The probe depth was at least 7 nm, as indicated by the finite XAS intensity at the La M4,5 edge (28), so that the entire Fe thickness contributed substantially to the signal. As shown in Fig. 1C (top), the spectrum at the Fe L2,3 edge corresponds to that of metallic Fe (32). The XAS spectrum obtained at the Ba M4,5 edge (Fig. 1C, middle) is similar to that reported for Ba2+ in (33). Despite the poor signal-to-noise ratio, the Ti L2,3 edge spectrum (Fig. C, bottom) shows the typical signature expected for a valence close to 4+ (34). From the XAS, HRTEM, and STEM analyses, we conclude that theFe/BTO interface is smooth with no detectable oxidation of the Fe layer within a limit of less than 1 nm.After cooling in a magnetic field of 5 kOe aligned along the [110] easy axis of pseudocubic LSMO (which is parallel to the orthorhombic [100] axis of NGO), we characterized the transport properties of the junctions at low temperature (4.2K). Figure 2A (middle) shows a typical resistance–versus–magnetic field R(H) cycle recorded at a bias voltage of –2 mV (positive bias corresponds to electrons tunneling from Fe to LSMO). The bottom panel of Fig. 2A shows the magnetic hysteresisloop m(H) of a similar unpatterned sample measured with superconducting quantuminterference device (SQUID) magnetometry. When we decreased the magnetic field from a large positive value, the resistance dropped in the –50 to –250 Oe range and then followed a plateau down to –800 Oe, after which it sharply returned to thehigh-resistance state. We observed a similar response when cycling the field back to large positive values. A comparison with the m(H) loop indicates that the switching fields in R(H) correspond to changes in the relative magnetic configuration of the LSMO and Fe electrodes from parallel (at high field) to antiparallel (at low field). The magnetically softer LSMO layer switched at lower fields (50 to 250 Oe) compared with the Fe layer, for which coupling to the exchange-biased Co/CoO induces larger and asymmetric coercive fields (–800 Oe, 300 Oe). The observed R(H) corresponds to a negative TMR = (R ap–R p)/R ap of –17% [R p and R ap are the resistance in the parallel (p) and antiparallel (ap) magnetic configurations, respectively; see the sketches in Fig. 2A]. Within the simple Jullière model of TMR (23) and considering the large positive spin polarization of half-metallic LSMO (25), this negative TMR corresponds to a negative spin polarization for bcc Fe at the interface with BTO, in agreement with ab initio calculations (18–20).Fig. 2(A) (Top) Device schematic with black arrows to indicate magnetizations. p, parallel; ap, antiparallel. (Middle) R(H) recorded at –2 mV and 4.2 K showing negative TMR. (Bottom) m(H) recorded at 30 K with a SQUID magnetometer. emu, electromagnetic units. (B) (Top) Device schematic with arrows to indicate ferroelectric polarization. (Bottom) I(V DC) curves recorded at 4.2 K after poling the ferroelectric down (orange curve) or up (brown curve). The bias dependence of the TER is shown in the inset.As predicted (35–38) and demonstrated (29) previously, the tunnel current across a ferroelectric barrier depends on the direction of the ferroelectric polarization. We also observed this effect in our Fe/BTO/LSMO junctions. As can be seen in Fig. 2B, after poling the BTO at 4.2 K to orient its polarization toward LSMO or Fe (with a poling voltage of VP–≈ –1 V or VP+≈ 1 V, respectively; see Fig. 2B sketches),current-versus-voltage I(V DC) curves collected at low bias voltages showed a finite difference corresponding to a tunnel electroresistance as large as TER = (I VP+–I VP–)/I VP–≈ 37% (Fig. 2B, inset). This TER can be interpreted within an electrostatic model (36–39), taking into account the asymmetric deformation of the barrier potential profile that is created by the incomplete screening of polarization charges by different Thomas-Fermi screening lengths at Fe/BTO and LSMO/BTO interfaces.Piezoelectric-related TER effects (35, 38) can be neglected as the piezoelectric coefficient estimated from PFM experiments is too small in our clamped films (29). TER measurements performed on a BTO(1 nm)/LSMO(30 nm) bilayer with the use of a CTAFM boron-doped diamond tip as the top electrode showed values of ~200%(29). Given the strong sensitivity of the TER on barrier parameters and barrier-electrode interfaces, these two values are not expected to match precisely. We anticipate that the TER variation between Fe/BTO/LSMO junctions and CTAFM-based measurements is primarily the result of different electrostatic boundary conditions.Switching the ferroelectric polarization of a tunnel barrier with voltage pulses is also expected to affect the spin-dependent DOS of electrodes at a ferromagnet/ferroelectric interface. Interfacial modifications of the spin-dependent DOS of the half-metallic LSMO by the ferroelectric BTO are not likely, as no states are present for the minority spins up to ~350 meV above E F (40, 41). For 3d ferromagnets such as Fe, large modifications of the spin-dependent DOS are expected, as charge transfer between spin-polarized empty and filled states is possible. For the Fe/BTO interface, large changes have been predicted through ab initio calculations of 3d electronic states of bcc Fe at the interface with BTO by several groups (18–20).To experimentally probe possible changes in the spin polarization of the Fe/BTO interface, we measured R(H) at a fixed bias voltage of –50 mV after aligning the ferroelectric polarization of BTO toward Fe or LSMO. R(H) cycles were collected for each direction of the ferroelectric polarization for two typical tunnel junctions of the same sample (Fig. 3, B and C, for junction #1; Fig. 3, D and E, for junction #2). In both junctions at the saturating magnetic field, high- and low-resistance states are observed when the ferroelectric polarization points toward LSMO or Fe, respectively, with a variation of ~ 25%. This result confirms the TER observations in Fig. 2B.Fig. 3(A) Sketch of the electrical control of spin polarization at the Fe/BTO interface.(B and C) R(H) curves for junction #1 (V DC = –50 mV, T = 4.2 K) after poling the ferroelectric barrier down or up, respectively. (D and E) R(H) curves for junction #2 (V DC = –50 mV, T= 4.2 K) after poling the ferroelectric barrier down or up, respectively.More interestingly, here, the TMR is dramatically modified by the reversal of BTO polarization. For junction #1, the TMR amplitude changes from –17 to –3% when the ferroelectric polarization is aligned toward Fe or LSMO, respectively (Fig. 3, B and C). Similarly for junction #2, the TMR changes from –45 to –19%. Similar results were obtained on Fe/BTO (1.2 nm)/LSMO junctions (28). Within the Jullière model (23), these changes in TMR correspond to a large (or small) spin polarization at the Fe/BTO interface when the ferroelectric polarization of BTO points toward (or away from) the Fe electrode. These experimental data support our interpretation regarding the electrical manipulation of the spin polarization of the Fe/BTO interface by switching the ferroelectric polarization of the tunnel barrier.To quantify the sensitivity of the TMR with the ferroelectric polarization, we define a term, the tunnel electromagnetoresistance, as TEMR = (TMR VP+–TMR VP–)/TMR VP–. Largevalues for the TEMR are found for junctions #1 (450%) and #2 (140%), respectively. This electrical control of the TMR with the ferroelectric polarization is repeatable, as shown in Fig. 4 for junction #1 where TMR curves are recorded after poling the ferroelectric up, down, up, and down, sequentially (28).Fig. 4TMR(H) curves recorded for junction #1 (V DC = –50 mV, T = 4.2 K) after poling the ferroelectric up (VP+), down (VP–), up (VP+), and down (VP–).For tunnel junctions with a ferroelectric barrier and dissimilar ferromagnetic electrodes, we have reported the influence of the electrically controlled ferroelectric barrier polarization on the tunnel-current spin polarization. This electrical influence over magnetic degrees of freedom represents a new and interfacial magnetoelectric effect that is large because spin-dependent tunneling is very sensitive to interfacial details. Ferroelectrics can provide a local, reversible, nonvolatile, and potentially low-power means of electrically addressing spintronics devices.Supporting Online Material/cgi/content/full/science.1184028/DC1Materials and MethodsFigs. S1 to S5References∙Received for publication 30 October 2009.∙Accepted for publication 4 January 2010.References and Notes1. C. Chappert, A. Fert, F. N. Van Dau, The emergence of spin electronics indata storage. Nat. Mater. 6,813 (2007).2.I. Žutić, J. Fabian, S. Das Sarma, Spintronics: Fundamentals andapplications. Rev. Mod. Phys. 76,323 (2004).3.J. C. Slonczewski, Current-driven excitation of magnetic multilayers. J.Magn. Magn. Mater. 159, L1(1996).4.J. Nitta, T. Akazaki, H. Takayanagi, T. Enoki, Gate control of spin-orbit interaction in an inverted In0.53Ga0.47As/In0.52Al0.48Asheterostructure. Phys. Rev. Lett. 78, 1335 (1997).5.H. Ohno et al., Electric-field control offerromagnetism. Nature 408, 944 (2000).6. D. 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Abbate et al., Soft-x-ray-absorption studies of the location of extracharges induced by substitution in controlled-valence materials. Phys. Rev.B 44, 5419 (1991).35. E. Y. Tsymbal, H. Kohlstedt, Tunneling across aferroelectric. Science 313, 181 (2006).36.M. Ye. Zhuravlev, R. F. Sabirianov, S. S. Jaswal, E. Y. Tsymbal, Giantelectroresistance in ferroelectric tunnel junctions. Phys. Rev.Lett. 94, 246802 (2005).37.M. Ye. Zhuravlev, R. F. Sabirianov, S. S. Jaswal, E. Y. Tsymbal, Erratum:Giant electroresistance in ferroelectric tunnel junctions. Phys. Rev.Lett. 102, 169901 2009).38.H. Kohlstedt, N. A. Pertsev, J. Rodriguez Contreras, R. Waser, Theoreticalcurrent-voltage characteristics of ferroelectric tunnel junctions. Phys. Rev.B 72, 125341 (2005).39.M. Gajek et al., Tunnel junctions with multiferroic barriers. Nat.Mater. 6, 296 (2007).40.M. Bowen et al., Spin-polarized tunneling spectroscopy in tunneljunctions with half-metallic electrodes.Phys. Rev. Lett. 95, 137203 (2005).41.J. D. Burton, E. Y. Tsymbal, Prediction of electrically induced magneticreconstruction at the manganite/ferroelectric interface. Phys. Rev.B 80, 174406 (2009).42.We thank R. Guillemet, C. Israel, M. E. Vickers, R. Mattana, J.-M. George,and P. Seneor for technical assistance, and C. Colliex for fruitful discussions on the microscopy measurements. This study was partially supported by theFrance-U.K. Partenariat Hubert Curien Alliance program, the French RéseauThématique de Recherche Avancée Triangle de la Physique, the European Union (EU) Specific Targeted Research Project (STRep) Manipulating the Coupling inMultiferroic Films, EU STReP Controlling Mesoscopic Phase Separation, U.K. Engineering and Physical Sciences Research Council grant EP/E026206/I, French C-Nano Île de France, French Agence Nationale de la Recherche (ANR) Oxitronics, French ANR Alicante, the European Enabling Science and Technology through European Elelctron Microscopy program, and the French Microscopie Electronique et Sonde Atomique network. X.M.acknowledges support from Comissionat per a Universitats i Recerca (Generalitat de Catalunya).。
大学物理光学实验报告(一)
大学物理光学实验报告（一）引言概述:本实验报告旨在介绍和分析大学物理光学实验的结果和观察。
通过对不同光学现象和装置的研究，我们能够更好地理解光的性质和光学实验的原理。
正文内容:I. 單色光干涉實驗A. Young's Double-Slit干涉實驗1. 描述Young's Double-Slit干涉實驗裝置2. 觀察到的干涉條紋現象3. 分析干涉條紋之間的距離與波長的關係4. 探討干涉條紋的明暗交替原因B. Lloyd's Mirror干涉實驗1. 解釋Lloyd's Mirror干涉實驗的原理2. 觀察到的干涉圖案3. 討論干涉圖案的變化與鏡面角度的關係4. 探討Lloyd's Mirror干涉實驗的應用II. 衍射實驗A. 單狹縫衍射實驗1. 描述單狹縫衍射實驗的裝置2. 觀察到的衍射條紋現象3. 分析衍射條紋的寬度與狹縫寬度的關係4. 探討單狹縫衍射實驗的應用B. 焦鏡和接區衍射實驗1. 介紹焦鏡和接區衍射實驗的原理2. 觀察到的衍射圖案3. 討論不同焦距的透鏡的影響4. 探討焦鏡和接區衍射實驗的應用III. 偏振實驗A. 偏振光通過偏振片的實驗1. 描述偏振光通過偏振片的裝置2. 觀察不同角度的偏振片的現象3. 分析不同偏振片的透光情況4. 探討偏振片在光學設備中的應用B. 雙折射實驗1. 解釋雙折射現象的原理2. 觀察不同材料的雙折射現象3. 討論雙折射在電子顯示器等設備中的應用4. 探討雙折射的應用在光學儀器中的重要性IV. 電磁波的反射和折射實驗A. 描述反射實驗裝置B. 觀察到的反射現象C. 分析反射角和入射角的關係D. 描述折射實驗裝置E. 觀察到的折射現象F. 分析入射角、入射光速度和折射光速度的關係V. 光的干涉技術在科學和工程中的應用A. 干涉技術在干涉式顯微鏡中的應用B. 干涉技術在光柵中的應用C. 干涉技術在光纖傳輸中的應用D. 干涉技術在光學儀器校準中的應用E. 干涉技術在光學表面檢測中的應用結論:通过本次实验的各个部分，我们对光学实验的原理和现象有了更深入的理解。
波动光学的数值模拟研究毕业论文 5 (1)
波动光学的数值模拟研究毕业设计学院:物理电气信息学院摘要在波动光学相关理论的基础上，通过编程实现了几种常见的干涉和衍射现象的仿真，将其结果形象、直观地体现出来，对于波动光学的教学和学习具有很好的帮助作用。
论文在干涉和衍射理论的基础上，编写了MATLAB程序代码，实现了杨氏干涉、等倾和等厚干涉、夫琅和费衍射和光栅衍射模拟仿真；此外，为方便用户使用，本文设计了对应的图形用户界面（包括设计方案、界面控件的布置和控件后台程序代码的添加），实现了仿真过程中的人机交互。
研究结果表明：通过仿真程序的运行，能形象、直观地展现几种干涉和衍射现象；通过图像用户界面的编制，实现了仿真实验项目的选取，实验参数的灵活设置以及结果的显示。
本文的特色在于：将干涉和衍射的仿真实验做成一个完整系统，并设计了个性化的图形用户界面。
通过仿真实验的图形户用界面，用户实现实验项目的选取，实验参数的灵活设置，实验结果的对比分析。
关键词: 波动光学 MATLAB 计算机仿真AbstractBased on the theory of wave optics-related, it realizes the programming of several common phenomena of interference and diffraction of the simulation by applying MATLAB matrix powerful computing and graphics rendering capabilities through coding. The image of the results will be directly reflected, which help a lot on will wave optics teaching and learning.The thesis achieves the realization of the optical film, spherical wave interference, Y oung's interference, equal-inclination and equal-thickness interference, Fraunhofer diffraction, Fresnel diffraction and grating diffraction simulation through coding, based on the theory of interference and diffraction. To make the studying easier, it made a graphical user interface (including the design, layout and interface control program code controls the addition of the background), achieving human-computer interaction of the simulation in the process.The results show that: by running the simulation program, it can display several interference and diffraction phenomena conveniently and vividly through the establishment of the graphical user interface, it achieves selection of simulation programs, setting experimental parameters of a simulation at random, as well as the flexible display of the resultsThe characteristics of this paper lie in that: this paper cooperated interference and diffraction simulation experiments into one complete system and designed a personalized MATLAB graphical user interface on MA TLAB. Through this platform of the simulation on graphics user interface, users can achieve selection of simulation programs, setting experimental parameters of a simulation randomly, the flexible display of the results as well as the comparative analysis of experimental result. Keywords: wave optics; MATLAB; computer simulation;1. 绪论 (1)1.1波动光学的历史 (1)1.2波动光学的研究对象 (2)1.3光学实验仿真的国内外研究现状 (2)1.4光学实验仿真 (3)2.光的干涉及实验仿真 (4)2.1.光的叠加原理 (4)2.2 杨氏干涉及实验仿真 (6)2.2.1 双光束干涉 (6)2.2.2杨氏干涉 (7)2.3薄膜干涉及实验仿真 (10)2.3.1薄膜干涉的光程差 (11)2.3.2等倾干涉及实验仿真 (13)2.3.3 等厚干涉及实验仿真 (14)2.4 本章小结 (17)3. 光的衍射及实验仿真 (17)3.1 光的衍射现象及其分类 (17)3.2 夫琅和费衍射及实验仿真 (18)3.3 光栅衍射及其仿真实现 (20)3.4 本章小结 (22)4. 结束语 (23)参考文献 (24)致谢...................................................................................... 错误！未定义书签。
波动光学实验报告
一、实验目的1. 理解波动光学的原理，掌握光的干涉、衍射和偏振现象。
2. 通过实验验证波动光学的基本原理，加深对光学知识的理解。
3. 培养学生的实验操作能力和分析问题的能力。
二、实验原理波动光学是研究光的波动性质的科学，主要研究光的干涉、衍射、偏振现象以及光与物质的相互作用。
本实验主要验证以下原理：1. 干涉现象：当两束相干光波相遇时，它们会相互叠加，形成干涉条纹。
干涉条纹的间距与光的波长和两束光之间的距离有关。
2. 衍射现象：当光波通过一个障碍物或狭缝时，会发生衍射现象。
衍射条纹的间距与光的波长和障碍物或狭缝的尺寸有关。
3. 偏振现象：光波是一种横波，可以通过偏振片使光波的电矢量振动方向限定在一个平面内。
通过观察偏振光的变化，可以验证光的偏振现象。
三、实验仪器与设备1. 激光器2. 双缝干涉装置3. 衍射光栅4. 偏振片5. 光屏6. 光具座7. 刻度尺8. 计时器四、实验步骤1. 干涉实验（1）将激光器发出的光通过扩束镜，使其成为平行光。
（2）将平行光照射到双缝干涉装置上，调整双缝间距，使干涉条纹清晰可见。
（3）观察并记录干涉条纹的位置、间距和亮度。
2. 衍射实验（1）将激光器发出的光通过光栅，使光发生衍射。
（2）调整光栅角度，观察并记录衍射条纹的位置、间距和亮度。
3. 偏振实验（1）将激光器发出的光通过偏振片，使其成为偏振光。
（2）调整偏振片角度，观察并记录偏振光的变化。
五、实验数据与分析1. 干涉实验（1）根据实验数据，计算干涉条纹的间距。
（2）根据干涉条纹的间距和光的波长，验证干涉现象。
2. 衍射实验（1）根据实验数据，计算衍射条纹的间距。
（2）根据衍射条纹的间距和光栅的尺寸，验证衍射现象。
3. 偏振实验（1）根据实验数据，观察偏振光的变化。
（2）根据偏振光的变化，验证光的偏振现象。
六、实验结论1. 通过干涉实验，验证了光的干涉现象，加深了对波动光学原理的理解。
2. 通过衍射实验，验证了光的衍射现象，加深了对波动光学原理的理解。
2024版大学物理波动光学总结
光波性质及描述方法光波是一种电磁波，具有波动性质，可以用振幅、频率、波长等物理量来描述。
光波在真空中的传播速度最快，且在不同介质中传播速度不同，服从折射定律。
光波具有横波性质，其振动方向与传播方向垂直。
干涉现象与条件010203衍射现象及规律123偏振光可以通过偏振片或反射、折射等方式产生。
偏振现象在光学仪器、光通信、生物医学等领域有广泛应用，如偏振显微镜、偏振光干涉仪等。
偏振现象是指光波中只包含特定振动方向的光波分量。
偏振现象及应用实验操作步骤准备相干光源、双缝装置、屏幕等实验器材；调整光源和双缝装置，使光源发出的光通过双缝照射到屏幕上；观察并记录屏幕上的干涉条纹。
双缝干涉实验原理通过双缝的相干光源产生干涉现象，观察屏幕上明暗相间的干涉条纹，研究光的波动性。
数据分析方法测量干涉条纹间距，计算光源的波长；根据干涉条纹的形状和分布，分析光源的相干性和双缝间距对干涉条纹的影响。
双缝干涉实验原理及操作薄膜干涉实验方法薄膜干涉原理实验操作步骤数据分析方法牛顿环测量光学表面反射相移牛顿环原理实验操作步骤数据分析方法长度测量表面形貌检测折射率测量光学器件性能测试干涉在精密测量中应用单缝衍射实验原理及操作原理：当单色光通过宽度与波长可比拟的单缝时，在屏上形成明暗相间的衍射条纹。
准备实验器材：激光器、单缝装置、分析实验数据，计算波长等参数。
调整激光器，使光束正对单缝装置，并调整单缝宽度。
圆孔衍射特点分析晶格衍射是X射线在晶体中发生的衍射现象，可用于研究晶体结构。
通过测量晶格衍射角度和强度，可以确定晶体中原子排列方式和晶格常数等参数。
晶格衍射技术在材料科学、化学、地质学等领域具有广泛应用。
晶格衍射在晶体结构研究中的应用衍射在光谱分析中的应用衍射可将复合光分解为不同波长的单色光，是光谱分析的基本原理之一。
通过测量不同波长光的衍射角度和强度，可以确定物质的成分和含量等信息。
光谱分析技术在化学、物理学、生物学等领域具有广泛应用，如原子吸收光谱、拉曼光谱等。
物理光学英文总结（精选五篇）
物理光学英文总结（精选五篇）第一篇：物理光学英文总结1.2.3.4.5.6.7.麦克斯韦方程组（Maxwell’s equation）电感强度, electric displacement 电场强度, electric field strength 磁感强度, magnetic flux density 磁场强度，magnetic field strength 波动方程的平面简谐波解(Simple Harmonic Wave)布儒斯特定律(Brewster’s Law)Brewster’ law, in his own words, states that “when a ray of light is polarized（偏振）by reflection, the reflected（反射）ray forms a right angle with the refracted（折射）ray.On the laws which regulate the polarization of light 偏振光by reflection from transparent bodies.” 8.光波的叠加, Superposition of waves 9.驻波(Standing Wave)10.拍频（Beat frequency）11.相速度（Phase velocity）12.群速度(Group velocity)13.合成波resultant wave 14.振幅amplitude 15.干涉现象（Interference）：在两个（或多个）光波叠加的区域形成强弱稳定的光强分布的现象，称为光的干涉现象。
The term Interference refers to the phenomenon that waves, under certain conditions, intensify or weaken each other.16.相干光波（Coherent wave）相干光源，Coherent light source 17.杨氏干涉实验（Young’s interference experiment）18.干涉条纹（Interference fringes）19.Path difference（路径差）20.Phase difference（位相差）21.The order of interference（干涉级）22.The light distribution（光分布）23.A maximum amount of light(maxima)24.A minimum amount of light(minima)25.干涉条纹的可见度The visibility(contrast)of interference fringes 26.对比度（Contrast）：It can be defined as the ratio of the difference between maximum areance（面积比）Emax, and mimimumareance, Emin, to the sum of such areances:K=(Emax-Emin)/(Emax+Emin)The amount of power incident per unit area is called areance(illuminance).Visibility：K=(Imax-Imin)/(Imax+Imin)27.相干性与干涉（Coherence & interference）28.空间相干性（spatial coherence)和时间相干性（temporal coherence）29.等厚干涉（Interference of equal thickness）30.平行平板(Plane-Parallel Plates)31.等倾干涉（Interference of equal inclination）32.法布里－泊罗干涉仪（Fabry-Perot interferometer）33.分辨极限和分辨本领（Resolvance of the interferometer）34.光学系统的分辨本领（Resolving power of an optical system）35.光的衍射（Diffraction）36.衍射实验(Diffraction experiment)37.衍射现象的分类(Classification of light diffraction)（1）夫琅和费衍射(Fraunhofer diffraction)（2）菲涅耳衍射（Fresnel diffraction）38.矩孔衍射(Diffraction by a rectangular aperture)39.强度分布计算（Intensity distribution calculation）40.单缝衍射(Diffraction by a single slit)41.夫琅和费圆孔衍射(Fraunhofer diffraction by a circular aperture)42.椭圆的衍射图样(Diffraction pattern)43.光学成像系统的衍射和分辨本领Diffraction and resolving power of an optical system 44.光学系统的分辨本领（Resolving power of an optical system）45.瑞利判据（Rayleigh’s criterion）46.双缝衍射（Double-slit diffraction）47.多缝衍射（Multiple-slit diffraction）48.衍射光栅(Diffraction gratings)49.光栅方程（The grating equation）50.光栅分辨本领(Resolvance of a grating)51.光的偏振（Polarization of light）52.偏振光与自然光，Polarized light and Natural light 53.线偏振光（Linearly polarized light）54.圆偏振光（Circularly polarized light）55.椭圆偏振光（Elliptically polarized light）56.部分偏振光(Partially polarized light)57.偏振光的产生（Production of polarized light）反射和折射、二向色性、散射、双折射Polarization by reflection Polarization by transmission Polarization by dichroism Polarization by scattering Polarization by birefringence 58.马吕斯定律(Malus’ law)和消光比(Extinction ratio）59.起偏器（Polarizer）：用来产生偏振光的偏振器件。
大学物理波动光学英文实验报告
Diffraction grating modeling by RCWA and CM methods: diffraction efficiency synchronism studiesIvan Richter,Petr Honsa,and Pavel FialaCzech Technical University in Prague,Faculty of Nuclear Sciences and Physical EngineeringDepartment of Physical Electronics,Břehová7,11519Prague l,CZECH REPUBLICPhone:+420221912285,Fax:+42026884818,Email:richter@troja.fjfi.cvut.czAbstract:This contribution concentrates on modeling of diffraction processes in opticaldiffraction gratings(ODG).First,the approach to characterization of mechanisms and diffractionprocesses is briefly presented,together with the regions with typical diffraction regimes.Differenttypes of diffraction efficiency volume phase synchronism are then described.Different situationsare analyzed and compared concerning ODG of different types,different refractive index/reliefmodulation profiles,various modulation strengths,and incident wave polarization influence.Asexamples,the cases of conical and Littrow mounts are discussed in detail.As rigorous modelingtools,both rigorous coupled wave analysis,and coordinate transformation methods are used,implemented,and modified.2002Optical Society of AmericaOCIS codes:050.1950Diffraction gratings,050.1970Diffractive optics1.Introduction and modeling toolsIn the last years,diffractive optics modeling,i.e.both analysis(direct problem)and synthesis(inverse problem)in diffractive optics has obtained an immense attention and interest,especially due to an increasing amount of practical applications of optical diffraction gratings(ODG)and diffractive optical elements and systems.Technological possibilities of grating fabrication methods to produce e.g.high-aspect ratio diffractive structures with periods(or minimum feature sizes)comparable and smaller than the wavelength of light have also enlarged rapidly.Hence, originally-used scalar theoretical methods(analytical methods of transmittance,two wave Kogelnik's methods,thin film decomposition,etc.)became inapplicable soon,and the rigorous methods had to start their developments and beings.Apart from design,fabrication and application driven rigorous modeling,diffraction processes characterization in ODG is also important itself since it can provide a deep insight into the physical mechanisms,can separate and identify their influences,and allows to find some regions(of important parameters)with typical diffraction regimes.In this sense,it is very useful and needful for all other types of modeling.Therefore,based on our previous studies[1-8],the purpose of this contribution is mainly to present,discuss and interpret on various examples new and physically interesting results concerning the behavior of the diffraction efficiency synchronism for selected grating and experimental parameters of diffraction gratings.As rigorous modeling tools,both rigorous coupled wave analysis(RCWA)and coordinate transformation methods(CM)have been implemented and applied within this contribution.RCWA,as a standard technique for the analysis of diffraction grating properties,nowadays represents an efficient and stable modelling tool[9].Our RCWA model has implemented several modifications and improvements,and was successfully applied in our previous studies[10].The coordinate transformation method has also shown a great potential in rigorous diffraction modelling,and become a strong counterpart of RCWA methods,efficiently applicable especially to specific types of surface-relief gratings[11].This method is based on the introduction of a new coordinate system transforming a generally complicated grating surface corrugation into a simple plane surface,hence simplifying the boundary-matching problem by a great extent.Our CM model,based mainly on the Li's valuable reformulation[12]and modifications of the classical algorithm,has also been recently successfully implemented and tested.We have confirmed that while CM has appeared fast and efficient for smooth profiles,and for both input polarizations,it has showed considerably slower convergence for profiles with discontinuities.On the other hand,RCWA is practically ideal for gratings with multilevel profiles.Both methods have been found complementary,with different areas of applicability,and thus both methods are used within this contribution.2.Diffraction efficiency synchronismAs has been shown in[1-3,7],by using the proper way of interpretation,i.e.by studying the diffraction efficiency of a given diffraction order in the representation defined by the relevant independent variables(as e.g.the period to wavelength ratio(Λ/λ) and the grating depth to wavelength ratio(d/λ) − for a fixed angle of incidence),it is possible to efficiently describe and explain the complex behavior of grating diffraction efficiencies.The main advantage of such a description is that the whole class of gratings can be described altogether,and character of the diffraction efficiency synchronization(i.e.volume phase synchronism[1,2])can thus be effectively studied.This also allows one to determine the regions with typical diffraction regimes in the(Λ/λ, d/λ)representation,as has been studied previously[1,2],the synchronism periodicity and structuring[7],as well as to study the behavior within resonant regions of diffraction(threshold and guiding effects[3,8]).From a practical point of view,however,the effects of varying some important grating and diffraction setup parameters,using mainly the(Λ/λ, d/λ)synchronism,are of great importance.Hence,in this contribution,these influences have been studied and will be presented(the effects of the angle of incidence,of grating relief profiles,of input polarization,and of the value of refractive index).3.The case of conical diffractionAs an example,Fig.1shows a comparison of volume phase synchronisms for the case of conical mount(90deg.) and classical mount(0deg.),for both TE and TM polarizations,for the case of binary gratings,with the incidence angle of30deg.As can be seen,whereas the classical mount provides the Bragg synchronization,in the case of conical mount,there is no such effect.4.Different types of synchronisms,the case of Littrow mountThe diffraction efficiency dependence characterization is clearly a complicated multi-parameter problem,complexly describable using some type of proper characterization.In this sense,although the selected(Λ/λ, d/λ)synchronism appears as one of the most beneficial,other types can be also very useful(angular synchronism,combinedsynchronisms).As the second example,Fig.2shows a comparison of such combined synchronisms,again for the case of binary gratings,comparing both TE and TM polarizations.Here,at each periodΛ/λ,the incident angle is appropriately changed in order to ensure the proper Littrow mount.In the contribution,the interpretation of such behavior will be given,and usefulness of the approach will be shown.5.ConclusionsTo summarize the contribution,we have contributed to a better understanding of diffraction processes in optical diffraction gratings,by presenting and interpreting various simulation results based on rigorous diffraction modeling of RCWA and CM.The influence of important parameters on the synchronism has been evaluated,and different situations have been analyzed and discussed.6.AcknowledgmentsThis work has been partially supported by the Grant Agency of Czech Republic with contract No.202/01/D004and by the Ministry of Education of the Czech Republic Research plan CEZ:J04/98:210000022.7.References[1]I.Richter,Z.Ryzí,and P.Fiala,"Analysis of binary diffraction gratings:comparison of different approaches,"J.Modern Optics45,1335(1998).[2]P.Fiala,I.Richter,and Z.Ryzí,"Analysis of diffraction processes in gratings,"Proceedings of SPIE3820,131(1999).[3]I.Richter and P.Fiala,"Threshold and resonance effects in diffraction gratings,"Proceedings of SPIE4095,58(2000).[4]I.Richter,P.Fiala,"Volume phase synchronism in diffraction gratings:various studies,"EOS Topical Meeting Digest Series30,32(2001)(EOS Topical Meeting on Diffractive Optics,Budapest,Hungary).[5]P.Honsa,I.Richter,and P.Fiala,"Rigorous analysis of surface-relief diffraction gratings:a comparison of CM and RCWA methods,"EOSTopical Meeting Digest Series30,74(2001)(EOS Topical Meeting on Diffractive Optics,Budapest,Hungary).[6]P.Fiala,M.Matějka,I.Richter,and M.Škereň,"Diffractive optics:analysis,design,and fabrication of diffractive optical elements,"Proceedings of the New Trends in Physics Conference345,(2001)(Technical University in Brno Press,Brno,Czech Republic,2001).[7]I.Richter,P.Fiala,and P.Honsa,"Volume phase synchronism in diffraction gratings:a comparison for different situations,"Proceedings ofSPIE4438,in print(2001).[8]I.Richter and P.Fiala,"Mechanisms connected with a new diffraction order formation in surface-relief gratings,"Optik111,237(2000).[9]M.G.Moharam and T.K.Gaylord,"Diffraction analysis of dielectric surface-relief gratings,"J.Opt.Soc.Am.72,1385(1982).[10]I.Richter,P.-C.Sun,F.Xu,and Y.Fainman,"Design Considerations of Form Birefringent Microstructures,"Applied Optics34,2421(1995).[11]J.Chandezon,M.T.Dupuis,G.Cornet,and D.Maystre,"Multicoated gratings:a differential formalism applicable in the entire opticalregion,"J.Opt.Soc.Am.72,839(1982).[12]L.Li,J.Chandezon,G.Granet,and J.-P.Plumey,"Rigorous and efficient grating-analysis method made easy for optical engineers,"AppliedOptics38,304(1999).。
英语描述光学实验报告
IntroductionThis report details the results of an optical experiment conducted in the Physics Laboratory of [University Name]. The objective of the experiment was to investigate the behavior of light and its interaction with various optical devices. The experiment was designed to explore the principles of reflection, refraction, and dispersion of light, as well as the formation of images using lenses and mirrors.Materials and EquipmentThe following materials and equipment were used during the experiment:- Laser pointer- Plane mirrors- Concave mirrors- Convex mirrors- Transparent prisms- Diffraction grating- Transparent blocks- Optical bench- Retort stand- Sensitive screen- Protractor- Ruler- White paper- CompassExperiment 1: Reflection of LightIn the first part of the experiment, we observed the reflection of light from various surfaces. We used a laser pointer to direct a beam of light at different angles onto a plane mirror. The angle of incidence was measured using a protractor, and the angle of reflection was noted. The results were consistent with the law of reflection, which states that the angle of incidence is equal to the angle of reflection.Experiment 2: Refraction of LightNext, we investigated the refraction of light as it passes through different mediums. We placed a laser pointer behind a transparent block and observed the path of the light beam as it entered and exited the block. The angle of refraction was measured using a protractor. By varying the angle of incidence, we observed that the angle of refraction changed, which is in accordance with Snell's law.Experiment 3: Dispersion of LightTo observe the dispersion of light, we used a transparent prism. A laser pointer was directed through the prism, and the resulting spectrum was observed on a white paper. The spectrum showed a continuous range of colors, which is a result of the different wavelengths of light being refracted at different angles within the prism.Experiment 4: Formation of ImagesIn this experiment, we explored the formation of images using lenses and mirrors. We set up a concave mirror and a convex mirror on the optical bench. A laser pointer was used to create a point source of light, and the resulting images were observed on a sensitive screen. For the concave mirror, we observed a real image when the object was placed beyond the focal point, and a virtual image when the object was placed between the focal point and the mirror. For the convex mirror, we observed only virtual images, which were always diminished and upright.Results and DiscussionThe results of the experiment were consistent with the theoretical principles of optics. The law of reflection was confirmed through theobservation of equal angles of incidence and reflection. Snell's law was verified by the consistent change in the angle of refraction with the angle of incidence. The dispersion of light was demonstrated by the spectrum observed through the prism, which is a direct result of the different refractive indices for different wavelengths of light.The formation of images using lenses and mirrors was also consistent with the principles of image formation. The real and virtual images formed by the concave and convex mirrors, respectively, were observed and measured. The images were found to be real when they could be projected onto a screen and virtual when they could not.ConclusionThe optical experiment conducted in the Physics Laboratory provided a comprehensive understanding of the behavior of light and its interaction with optical devices. The principles of reflection, refraction, dispersion, and image formation were explored and verified through a series of experiments. The results obtained were consistent with the theoretical predictions, and the experiment was successful in achieving its objectives.Recommendations for Further StudyFuture studies could involve more complex optical setups, such as the use of multiple lenses and prisms to create and analyze more intricate optical phenomena. Additionally, the effects of different materials on the refractive indices of light could be investigated to further understand the principles of optics.。
波动光学折射实验报告
一、实验目的1. 深入理解光的波动性，验证光的折射现象。
2. 掌握实验操作步骤，提高实验技能。
3. 学习使用相关仪器，了解其原理及使用方法。
二、实验原理波动光学是研究光的传播、反射、折射、干涉、衍射等现象的学科。
光的折射现象是指光从一种介质斜射入另一种介质时，传播方向发生改变的现象。
根据斯涅尔定律，光在两种介质中的折射角与入射角之间存在以下关系：n1sinθ1 = n2sinθ2其中，n1、n2分别为两种介质的折射率，θ1为入射角，θ2为折射角。
本实验通过观察光在不同介质中的折射现象，验证斯涅尔定律的正确性，并测定不同介质的折射率。
三、实验器材1. 平行光源2. 凸透镜3. 凹透镜4. 水平仪5. 折射仪6. 毛玻璃7. 激光笔8. 光具座9. 白屏10. 针式调节器四、实验步骤1. 将平行光源、凸透镜、凹透镜依次安装在光具座上，确保透镜中心与光源中心对齐。
2. 将毛玻璃放置在光具座的另一端，作为观察屏幕。
3. 通过调节针式调节器，使激光笔发出的光线垂直照射到凸透镜上，观察光线的传播情况。
4. 沿着激光笔发出的光线方向，逐渐将凹透镜靠近凸透镜，观察光线在两种介质交界处发生折射现象。
5. 记录入射角θ1、折射角θ2以及两种介质的折射率n1、n2。
6. 更换不同介质，重复步骤4和5，记录相关数据。
7. 对实验数据进行整理、分析，验证斯涅尔定律的正确性。
五、实验数据及结果1. 凸透镜与空气的折射率：n1 = 1.50凹透镜与空气的折射率：n2 = 1.50入射角θ1 = 30°折射角θ2 = 20°2. 凸透镜与水的折射率：n1 = 1.33凹透镜与水的折射率：n2 = 1.33入射角θ1 = 30°折射角θ2 = 25°3. 凸透镜与玻璃的折射率：n1 = 1.50凹透镜与玻璃的折射率：n2 = 1.50入射角θ1 = 30°折射角θ2 = 20°六、实验结论通过本次实验，我们验证了斯涅尔定律的正确性，并成功测定了不同介质的折射率。
英语作文描写物理实验报告
英语作文描写物理实验报告Physics Experiment Report。
Introduction。
The purpose of this experiment is to investigate the relationship between the force applied to a spring and the resulting extension of the spring. Hooke's Law states that the extension of a spring is proportional to the force applied to it, provided that the elastic limit of the spring is not exceeded.Materials。
The materials used in this experiment include a spring, a set of weights, a ruler, and a stand.Procedure。
First, we set up the stand and attached the spring toit. Then, we measured the length of the spring when it was not under any load. Next, we added weights to the spring in increments of 100 grams and measured the length of thespring after each weight was added. We continued adding weights until the spring reached its elastic limit. Finally, we recorded our data and analyzed the results.Results。
大学物理实验报告英文版--声速测量
Physical Lab Report : Measurement of speed of soundWriter: No.Experiment date: 31.10.2012&7.11.2012Report date:10.11.2012In this class,we start to do an experiment b y only one person,which is named“measurement of speed of sound”.In fact,we are required to measure the wavelength and the frequency at the same same according to the formula“λf v =” .We can measure the frequency using the oscilloscope.And there are several about 15 minutes,I become familiar with them and begin operating my experiment.Experiment ing the resonance methodIn order to make the error smaller,I first move S2 to the position about mm x 100= ,then ,I move the S2 until first received amplitude reaches maximum.At the same time,I set the digital indicator to “mm 0”and record it,which makes following records easier.When f =38.629Hz,the records are as followed:There are two methods available to get an average distance from which we calculate the wavelength.The average,49.42mm =so mm 98.9=λ.then,m/s mm f v 346.898.98Hz 629.38=⨯==λ.The averagemm 48.42=.so ./12.34696.8Hz 629.38,96.8s m mm f v mm =⨯===λλCombining the method A and B,the average speed of sound is m/s 346.51v 1=.Experiment ing phase comparison methodIn this experiment,I was excited to see the so-called Lissajous curves.But I met a problem when I try to read the position of S 2 when the curv es collapses into straight line to “ ”,while it is OK to read when it shows“ ”.Thus,I found a solution to deal with this problem-----I only recorded the position of S 2 when the Lissajous curve showed “ ”.Then I must be careful that the phase between two record is 2π when doing data analysis later.Also,there are two methods to get the wavelength:A.Successive subtraction method:x 9-x 1 x 10-x 2 x 11-x 3 x 12-x 4x 13-x 5x 14-x 6x 15-x 7x 16-x 8Unit(mm ) 79.26 80.64 80.73 80.85 80.47 82.55 82.64 83.05 )(8mm x∆=λ 9.9010.0810.0910.1010.0510.3210.3310.38The average mm 15.10=λ.then,m/s mm f v 350.8115.01Hz 563.34=⨯==λ.e a linear fit x i -x 1=(i -1)λ/2i2 3 4 5 6 7 8 9 10 11 12 13141516)(11mm i x x i --=λ8.9 9.90 9.83 9.99 9.77 9.84 9.86 9.90 9.96 10.05 10.0310.0310.1110.1210.14The average ./17.34290.9Hz 563.34,90.9s m mm f v mm =⨯===λλCombining the method A and B,the average speed of sound is m/s 346.49v 2=Experiment ing timing methodIn fact,timing method is the first method I thought of when I want to measure the speed of sound.Because the basic formula “tLv ∆∆=”is almost the first physical formula we have learned. Now comes the problem that how to calculate the v since we have the formula as a principle.Then I recalled the first experiment we did to measure the spring constant.We made a linear fit of ∆x vs m ,the slope of which is just the k.Similarly,I collect all the data and then make a linear fit of L ∆ vs ∆t,the slope of which is just the speed of sound.The data recorded is as followed: t/μs 404 433 460 490 519 546 575 605 634 L/mm100110120130140150160170180After putting all the data to SI unit ,the form is: t/s 0.000404 0.000433 0.00046 0.00049 0.000519 0.000546 0.000575 0.000605 0.000634 L/m0.10.110.120.130.140.150.160.170.18Then I use a mathematic tool to make a linear fit of L vs t ,the graph is :According to the graph,we see R 2=0.9999,indicating that L and t are quite linearly correlative.Besides,we know the slope is the speed of sound,i.e,we conclude that m/s 348.40v 3=.Experiment ing timing method to measure the speed of sound in waterAfter finishing the first three experiments measuring the speed of sound in air,I filled the apparatus with water,and did the experiment similar to the experiment 3 to measure the sound speed in water. The data recorded is as followed: t/μs 94 100 107 114 121 127 134 141 148 L/mm100110120130140150160170180After putting all the data to SI unit ,the form is: t/s 0.00094 0.000100 0.000107 0.000114 0.000121 0.000127 0.000134 0.000141 0.000148 L/m0.10.110.120.130.140.150.160.170.18Then I use the mathematic tool to make a linear fit of L vs t ,the graph is :Also,from the graph,I see R 2=0.9997,indicating that L and t in water are also well linearly correlative.Similarly,weconclude that the speed of sound in water m/s 1477.4v water =.Discussion and conclusionThere are several factors contributing to the errors:①The distance between S1 and S2 is not always appropriate.For example,maybe I set the initial distance to be 100mm,but as I move S2 slowly away from S1,the distance become larger,which may make the transmission less sensitive,causing errors in the time.②In the experiment using resonance method,we need to judge that the oscillation amplitude in the detected signal reaches the maximum.Thus comes the problem how to judge.It ’s all up to ourselves!And this is also where errors come.③During a method,I had to keep the frequency unchanging,however,though I had try my best to keep it constant,it still changed,which can ’t be avoided by person.④As a matter of fact,when the sound transmit for a short distance,it may not strictly obey a simple harmonic wave,but we simplify the complexity when doing data analysis.Conclusion for the experimentwe use three methods to measure the sound of speed in air,the results are: m/s 346.51v 1= , m/s 346.49v 2= , m/s 348.40v 3= Besides the speed of sound in water is m/s 1477.4v water =.That is to say,the speed in water is approximately 4.3 times of that in air.In fact,this is very important in life.For example ,sonar is an application.It can measure the distance as well as explore things in water.This confirms that physics is always around our life and very useful .。
大学英文物理实验报告(简易)
“Simple Harmonic Motion Experiment”AbstractIn this lab we are using spring weights, rod, clamp, string force sensor and rule to determine the spring constant using two different methods.Experiment DescriptionBefore starting the experiment, we need to calculate the spring constant k by using:F = -kxWhich F is force that pull or push the force sensor, x is displacement while weights are hanging on the spring. If the spring we use obey Hooke’s law, displacement(x) will follow the equation:x = A cos(ωt+Φ) (1)While A is the amplitude of oscillation,ω is the angular frequency in rad/s, Φ is the staring angle and t reference time in second. For both Φ and ω, we can use the following equations:ω = (k/m)^(1/2) (2)T = 2π[(m/k)^(1/2)] (3)For the first part of the experiment, we hang a mass holder from the end of the spring and measure the displacement from this point. Starting to add masses on the hanger from mass = 0.15kg. Measure the length changing and add additional 0.1kg at the end of the spring. Repeat 6 times and record the data to a excel table.For the second part, set up the computer and Data studio, open a graph reference force vs time. Set rate to 50Hz. Bump the weight in order to fit the graph like a sine wave, using fit area to find the period T. Repeat adding mass on the spring by 0.1kg each time. By squaring both side of (3), we have:T^2 = (4π^2)m/kPlot T^2 versus m to a excel form. Using linear equation to determine the slope k.Experiment ResultPart 1，Force vs. DisplacementPart 2, T^2 vs. Mass2.Value k found in Part 2: 29.03.3.Percentage difference: 0.24%.4.While y axis, which T^2 is 0, Mass actually is not 0. Because spring has mass on it andwill affect the total mass. Also, Air resistance will also being a fact.5.While on the moon, mass will also about 1/6 like on Earth. so the displacement willshorter. Because of no air resistance acting on the experiment, Part 2 may become more accurately.ConclusionThe experiment tell me about the constant resilience of a object. The force acts on this object will appears shape changes, which will follow F=-kx. By using two different ways to evaluate the constant k of the spring, we also know that we c an’t over extend object because there is a limit. While in the limitation, force and displacement will follow the Hooke’s law. After the force exceed over the limit, rule will break.。
英文的物理实验报告
英文的物理实验报告Title: Physics Experiment Report - The Pendulum ExperimentIntroduction:The pendulum experiment is a classic physics experiment that demonstrates the principles of oscillation and the relationship between the length of a pendulum and its period. In this report, we will outline the setup and procedure of the experiment, as well as the results and conclusions drawn from our observations. Setup and Procedure:To conduct the pendulum experiment, we first assembled a simple pendulum using a string and a weight. The length of the string was measured and recorded. The pendulum was then set in motion by displacing the weight and allowing itto swing back and forth. The time it took for the pendulum to complete one full oscillation, known as the period, was measured using a stopwatch. This process was repeated for pendulums of different lengths.Results:After conducting the experiment and recording our observations, we plotted a graph of the length of the pendulum versus its period. We observed that as the length of the pendulum increased, the period also increased. This relationship was found to be linear, with the period being directly proportional to the square root of the length of the pendulum.Conclusions:From our experiment, we can conclude that the period of a pendulum isdependent on its length. This relationship can be described by the formula T = 2π√(L/g), where T is the period, L is the length of the pendulum, and g is the acceleration due to gravity. This experiment demonstrates the principles of simple harmonic motion and provides a practical example of how the period of a pendulum can be calculated based on its length.Overall, the pendulum experiment serves as a valuable tool for understanding the principles of oscillation and the relationship between the length of a pendulum and its period. It is a fundamental experiment in the field of physics and provides a hands-on demonstration of the concepts of simple harmonic motion.。
物理实验报告(英文)
物理实验报告(英文)IntroductionThe Planck constant is a constant of physics which reflects the magnitude of energy quantum in the field of quantum mechanics. The sign of Planck constant is h and it is named by Max Planck in 1990. The proportionality constant between a photon’s energy and the frequency of its electromagnetic wave was the first definition of the Planck constant. This theory was generalized by Louis de Broglie in 1923 and confirmed by experiments. There is a difference between h and (h-bar). is called the Dirac constant or reduced Planck constant which is equal to the Planck constant divided by 2π.(1)The photoelectric effect is the effect that when a matter which can be metals, non-metallic solids, liquids or gases is bombarded by photons (light), electrons in the substance will absorb the energy of photons and they will be emitted, one electron could only absorb the energy of one photon. It is usually a way to find the Planck constant. As the limiting of the facilities, the main results which include the wavelength of lights and the planck constant are not easy to be gotten in accurate values. This lab was designed to find the Planck constant based on the light diffraction and the photoelectric effect, there are four aims of this experiment which are building a spectrometer, finding wavelengths for lasers and LEDS and finding the Planck constant.23TheoremWhen a beam of monochromatic light passing through a diffraction grating, the wavelength and the distance from the grating to the centerrelationships, n is the order of fringes and it is equal to ⋅⋅⋅⋅⋅⋅3,2,1,o , λ is the wavelength of this light, L , y , d are the distance from the grating to the center fringe, the fringes to the center fringe and the distance between two slits in the grating respectively, θ is the angle between the center line and the line connected by the fringe center and the slit. The formula of the photoelectric effect is w hf E -=, E is the energy of the electro escaping from the object, f is the frequency of the light which shots at the surface of the object, h is the Planck constant and w is the work function. For a certain object, the work function is a constant. For LED, This formula also can be rewritten as w hf eV -= where e is the quantity of electric charge and it is c 19106.1-⨯and V is the voltage of the LED. For EM wave, f C CT ==λ(C is the speed of light and f is its frequency.4Formula :θλsin d n =, )(tan 1L y -=ϑ, w hf E -=, w hf eV -=, fC CT ==λ.AimsAim I : building a spectrometer● Apparatus: carton, circular diffraction grating, a piece of paper, ruler, white light LED, scissors.Diagram 1 is the simple model the spectrometer● Diagram 1: simple model of the spectrometer● MethodsThe process of making a simple spectrometer was mainly 5 steps and operated by two people. First of all, a hole with proper sizes in the front of the carton was removed by the scissors. Secondly, a circular diffraction grating was set to the hole to cover it, which was used to produce the diffraction pattern. Thirdly, a piece of paper was fixed at the internal back surface of the carton, which was served as a screen to bring out the diffraction pattern. Then, at a proper position on the top surface, an elliptic hole which was long and narrow (this is to help to view because the light from THE LED is not be very strong) was removed to view the diffraction pattern which was inside the carton. Next, a ruler was put at the bottom near to the back surface and the purpose of this step was measuring the distance between different fringes.The experiment started after the spectrometer was finished. At the first, the light of the torch was shot to the center of the diffraction grating vertically and the diffraction pattern appeared on the screen. Then, observing the diffraction pattern through the viewing hole in top and record the position of each fringe. Next, the distances from the center to each fringe were read from the ruler and they are recorded on the drafter paper. Later, the length (L) between the front surface and the back surface was measured and recorded. At last, the result was recognized into the table which was on the tutorial.5Resulti. Problems with building and using the spectrometerDuring the process of building and using the spectrometer, there are some problems existing and which will lead to errors of the experiment result. When the spectrometer was made, the carton was not perfect cube, so the length (L) between the front surface and the back surface is not accurate. With the change of fringes, L is not a certain value and it will change, this is because sides of the nonstandard cube are not parallel to each other respectively. The hole with diffraction was hard to be put at the center of the front surface as the position was estimated by eyes. The positions of each fringe were recorded while the brightest fringe at the center of the back surface, so the brightest fringe is not vertical to the screen and which will lead to the distances between the fringes and the center fringe were not correct. While operating this experiment, the viewing hole in the top is narrow, so the position of each fringe cannot be labeled correctly. Due to the weakness of the light and seven different monochromatic lights gathering together, it is not easy to tell where is the fringe center of each monochromatic light and which also will cause the errors on marking the positions.ii. Results tableTable 1 shows the experiment data of aim 1 and the wavelengths of67 different monochromatic lights calculated from the it.Table 1: results of aim 1.As shown in table1, the wavelengths of the red light, yellow light, green light and the blue light are 643.6 nm, 548.9 nm, 482.3 nm and 377.5 nm respectively. So from the red light to the blue light, their wavelengths are deduced. After the white light shots at the diffracting grating, there are lightand dark sections alternating with each other. Three fringe fields which are in light sections appear on the screen and they are symmetry with the center fringe. In each fringe field, there are red, orange, yellow green, blue, indigo and violet from the right side to the left side respectively.AnalysisThe wavelength of the red, yellow, green and blue light is 643.6nm, 548.9 nm, 482.3 nm, 377.5 nm respectively. The formulas are θλsin d n = and center fringe to the slits is m 215.0. The total length of the diffraction grating is mm 1with 600 slits, so the distance (d ) between to slits is8different value of y, the wavelength of each monochromatic light was gotten and they are shown in table 1. Table 2 below is the comparison of the standard wavelength for the for lights.Table 2 is the comparison between the standard wavelength and the wavelength gotten from this experiment of the four monochromatic lights.Table 2: comparisonAccording to this table, only the wavelength of red light is in the range of the standard wavelength. The wavelengths of the yellow, green, blue light gotten from aim 1 are smaller than the real value, which are caused by the errors discussed before. Therefore, the results are not very accurate. Monochromatic light is the kind of light that has a single wavelength (2). The light comes from the torch is White light. White light is composed of seven lights which are red, orange, yellow…… and it has seven wavelengths (3). Therefore, white light is polychromatic light and this is the reason why the diffracting pattern has different colors. Light is a kind of EM wave. EM wave has visible spectrum and the invisible spectrum. When the frequency of light is between HZ 14103.4 and9HZ 14105.7 , it is visible light which includes red, orange, yellow, green, blue, indigo, violet light. When the frequency of light is out of this range, it is invisible light (4).● Apparatus: spectrometer, a piece of paper, ruler, red laser pen, blue laser pen, red and blue goggles.● MethodsGoggle is a kind of light filter and it can avoid the light damaging to the eyes bychanging the intensity and spectrum of the through lights. The ways of this aim is similar to the aim 1. First of all, one person used the red laser pen to shot at the diffraction grating and the other person observed the diffraction pattern by wearing a blue goggle. The reason why blue goggle was used to observe the red laser is that it can absorb the red light which will protect the eyes , in the same way, the red goggle was put on to protect the eyes when the blue laser pen was used (5). Then, the position of each fringe was recorded. Next, the distance from the different fringes to the center fringe was read from the ruler and it was recorded at another sheet of paper. Later, using the blue laser pen and wearing the red goggle to repeat the last steps.●ResultsTable 3 shows the experiment data of aim 2 and the wavelength of the red and blue laser gotten from it.Table 3: results of aim 2The wavelength calculated from the second order is smaller than the first order, which can be seen from table 3. Both diffraction patterns of the red laser and blue laser have five bright sections and they symmetry about the center fringe. The bright section and the dark section are alternating with each other. When the bright section got far from the center fringe, it became darker and darker. So the brightness of second order is darker than the first order.●AnalysisTable 4 shows the wavelength of the red light and the blue light from aim 1 and aim 2Table 4: Comparison of the results for aim 1 and aim 2Two fringe orders of diffraction could be seen in aim 2 and there is a10fringe on the sides as well as the back (6). The wavelengths of the red and blue LED calculated from the first order are 618.9 nm and 405.9 nm. From the second order, the wavelengths are 607.5 nm and 393.0 nm respectively. The results of the two aims are not the same: wavelengths of the red light in aim 2 for the first and second order are smaller than aim 1 while which of the blue light of aim 2 are bigger than aim 1 (8). The values of wavelengths of different orders in aim 2 are different. As the pattern of the first order is brighter than the second order, when marked the position of fringes, it will be more accurate. Thus, the result gotten from the first fringe will be more accurate than the second order and they are different. The different separations also will lead to the different results. If the slit separation becomes narrower, the diffraction pattern will become clearer. On the opposite side, the pattern will become unclear when the slits separation is wider (7).●Apparatus:Spectrometer, LEDs, power supply, black plastic bag, leads.●Methodsi. Connect the powers supply and the socket and let the voltage is theminimum value11ii. Connect the Red LED to the power supply and regulate the voltage ata proper value to make the LED shine normally.iii. Let the light of the red LED pass through the empty pen and shot at the spectrometer through the diffraction grating. The diffraction pattern will be more clear when the LED passed through the empty pen as the light was gathered and its intensity was strengthened (9).iv. Observe the diffraction pattern from the viewing hole with the black plastic bag covered the head and the viewing hole (the LED was not bright and not easy to be seen, to reduce the light loss and help view, the black plastic bag was used).v. Take done the position of the center of each fringe.vi. Read the distance from each fringe to the center fringevii. Recognize the result and move it to the table in tutorialviii. U sing the yellow, blue and green LEDs respectively to repeat the above processResultsTable 5 shows the experiment data of aim 3 and the wavelength, frequency of the four LEDs gotten from the result.Tabl e 5: results of aim 31213The phenomenon of this aim is not very clear to see, there are three bright circular sections. In each section, the brightness became smaller and smaller from the center to the sides. Of the four color LEDs, the blue LED is brightest, then are the green, yellow, red LED respectively. This was seen from the experiment.AnalysisThe wavelength was gotten from the same way of calculation as aim1. fC CT ==λλC f =⇒()/1038s m C ⨯=, so the frequency of each LED can be calculated. The wavelength of the red LED, yellow LED, green LED, blue LED from this aim are nm 662, nm 594, nm 555 and nm 482respectively. The frequencies of them are Hz 14105.4⨯,Hz 141005.5⨯,Hz 141040.5⨯ andHz 141022.6⨯.Table 6 shows the comparison between the wavelengths, frequencies of the four LEDS gotten of aim 3 and the standard valueTable 6: comparisonAs shown in table 6, both the wavelengths and the frequencies of the red LED, yellow LED and green LED are in the range of the standard value. However, the result of the blue LED was out of the range. This aim works well and the results are more accurate than the previous aims.●ApparatusSpectrometer, LEDs, power supply, black plastic bag, leads.●Methodsi. Connect the powers supply and the socket and let the voltage is theminimum value.ii. Connect the red LED to the power supply.iii. Regulate the value of voltage through the power supply and make it increase slowly.iv. When the LED just started to shine, writing done the voltage V, stopping to regulate the voltage and using the LED to shot the diffraction grating.v. Viewing the diffraction pattern on the screen through the viewing hole with the black plastic bag covered the head and the hole.vi. Mark the position of the center of each fringe on the screen paper. vii. Read the distances from each fringe to the center fringe and write the14data onto another sheet of paper.viii. R eplace the red LED into yellow LED, blue LED and green LED respectively and repeat the above process for each of them.ix. Using the data to draw a graph of eV on Y against f on x.ResultTable 7 shows the experiment data of aim 3 and the wavelength, frequency of the four LEDs gotten from the result.Tabl e 7: results of aim 3The frequencies were calculated from the same method as aim 3. On the screen, the diffraction pattern of the red LED was not clear and the pattern of the blue LED is brightest. The pattern of the green LED was more clear than the tallow LED and the red LED. For each LED, the patterns were similar to each other and they had three bright sections, the brightness was reduced from the center of the bright fringe to its edge in every bight section. In this table, eV is energy of theVphotoelectron escaping from the LED,1516Is the value of voltage when the LED started to shine and h is the Planck constant.Graph 1 is the relationship between eV and the frequency of the light. Graph 1: the relationship between eV and frequency.For this graph, x-axis is the frequencies of different kinds of light, y-axis is energy of the photoelectron.AnalysisThe equation of eV against frequency is w hf eV -=, w is work function. For the equation, the gradient is the Planck constant, and the intercept is the work function. According to graph1, the equation of the relationship between eV and frequency is 259.1819.0-=x y , as the unit magnitude of the x-axis is Hz 1410and it of the y-axis is J 1910-. Sos J h ⋅⨯=⨯=--3414191019.81010819.0. The real value of the Planck constant17is s J ⋅⨯-341063.6, so the result is not very accurate. There exist some errors. First of all, as the weakness of the LEDs and eyes cannot tell the fringes center accurately, the distance (y) from fringes to the center fringe is not accurate and it will lead to the inaccuracy of frequency. Secondly, the voltage used should be the instant voltage while the LED was just starting to shine. However, this is impossible to achieve. The above two errors are the largest causes of errors. The distance (L) between the grating to the center fringe is also not accurate as it read by eyes, which is the third error. Therefore, errors on reading the distance and the voltage are two approximate measurement errors (10). In addition, the uncertain errors also exist. The LED may shine abnormally as it was used before or some other internal problems are in the LED, this may is an error and it is uncertain..Operating this experiment in the dark, using the new LEDs and using other materials which are more stable instead of carton are three measurements can be done to improve the accuracy of this experiment (10). The answers from the LED with two colors cannot be used to find h as it is not monochromatic light and it has two frequencies (11). The error in the method for finding h can be calculated by this method which is Js s h h 3410)(-⨯±=, where s is the corrected standard deviation. ∑--=n i i h h n s 2)(11.The Planckconstant s J h ⋅⨯=-341063.6, Four colors of light were measured, so 4=n .18From table 7,1h , 2h ,3h ,4h are Js 3410942.4-⨯, Js 3410018.6-⨯,Js 3410221.6-⨯and Js 3410916.5-⨯respectively. So⇒⨯=+++=-3443211066175.54h h h h h ⇒⨯-=--=∑∑-412342)1066175.5(31)(11hi h h n s n i i ()[]24232221)()()(31h h h h h h h h s -+-+-+-=. Substituting them and s can be worked out which is 341006.1-⨯. Therefore,Js h 34343410)1006.11066175.5(---⨯⨯±⨯=(12).according to the website which is called Investopedia (2012), the standard deviation stands for the rate of deviation between the stochastic variable and the mathematic expectation, so a low s means that the result s were close together. The standard deviation of the result gotten from aim 4 is 341006.1-⨯from the real h. as the errors of the results have no regular pattern, the errors are random, not systematic(12).ConclusionThis lab has finished 4 aims which are building a spectrometer, finding wavelengths for lasers and LEDS and finding the Planck constant, the Planck constant was also gotten from the experiment based on the light diffraction and the photoelectric effect. To sum up, the spectrometer used to measure wavelengths is useful as it can produces the diffraction19pattern and shows the pattern on the screen. Also, the distance from the fringes to the center fringe can be read from the bottom ’s ruler directly as well as the distance from the center fringe to the grating. The spectrometer is easy to be made and operated. However, due to the unstable property, the data must be read from the viewing hole and the light will lose from it, the spectrometer is not very accurate. From Wikipedia, there is another way to measure the Planck constant which is Watt balance method. The Watt balance is a tool to compare two powers, one of which is measured in conventional electrical units and the other is in SI watts. According to the explanation of the conventional watt, K J R K 2 with SI unit can be measured where K R is the Von Klitzing constant and it can be measured from the effect of quantum Hall. In the particular situation 2/e h R K =can be assumed, thus, the Planck constantwith the photoelectric effect, the watt balance method to measure the Planck constant is hard to be operated and it only can work in the particular situation, in addition, the result gotten from this method also not very accurate. Therefore, the photoelectric effect is better and easier than the watt balance method to measure the Planck constant.Reference :Investopedia (2012) Standard deviation [Internet], Available from:<> [Accessed 15th May 2012].Wikipedia (2012) Watt balance [Internet], Available from:<e > [Accessed 15th May 2012].20。