研究生专业英语演讲PPT

School of Opto-Electronic Engineering
专业英语文献汇报
5/30/2015
2
Principles and Experimental Setup
Principles
Nanjing University of Posts and Telecomunications
• There is a peak in the frequency response curve of a directly modulated DFB semiconductor laser named resonance peak, which comes from the coupling between carriers and photons. • The frequency centered at the resonance peak has the highest modulation efficiency when a DFB laser is directly modulated by an RF signal the high modulation efficiency at resonance peak would decrease the RF threshold gain. • The tuning range is very limited due to the falling and flatting of the peak response when the DFB is biased at large current. • In this paper, we improve it by optical injection. With the help of optical injection, the resonance peak is enhanced evidently, making the threshold gain decreased and the tuning range enlarged.
School of Opto-Electronic Engineering
专业英语文献汇报
5/30/2015
3
Principles and Experimental Setup
Experimental Setup
Nanjing University of Posts and Telecomunications
School of Opto-Electronic Engineering
专业英语文献汇报
5/30/2015
8
Conclusion
Nanjing University of Posts and Telecomunications
A novel OEO to generate a wideband and frequency tunable microwave signal based on a directly modulated DFB
School of Opto-Electronic Engineering
专业英语文献汇报
5/30/2015
7
Results and Discussions
Nanjing University of Posts and Telecomunications
Fig. 4 shows the phase noise curve of the generated 12.2 GHz electrical signal,It is measured to be-103.8 dBc/Hz at 10 kHz frequency offset.
School of Opto-Electronic Engineering
专业英语文献汇报
5/30/2015
5
Results and Discussions
Nanjing University of Posts and Telecomunications
• Fig. 3 shows the generated microwave signals over a frequency tuning from 5.98 to 15.22 GHz.
School of Opto-Electronic Engineering
专业英语文献汇报
5/30/2015
9
Nanjing University of Posts and Telecomunications
OFC 2015，M3E.1.
Nanjing University of Posts Fraunhofer and Telecomunications Heinrich Hertz Institute
Widely Tunable OEO Based on a Directly Modulated DFB Laser under Optical Injection
tuned over a wide range .the generated microwave signals
over a frequency tuning from 5.98 to 15.22 GHz. The output power cannot keep constant due to the uneven frequency response of the slave DFB laser under optical injection.
semiconductor laser under optical injection was proposed and experimentally demonstrated. By adjusting injection ratio and detuning frequency, microwave signals tuned from 5.98 to 15.22 GHz were generated.The proposed OEO is simple and low-cost with wide tuning range, which can be useful in future applications.
School of Opto-Electronic Engineering
专业英语文献汇报
5/30/2015
6
Results and Discussions
Nanjing University of Posts and Telecomunications
Changing the injection ratio and detuning frequency by adjusting the TLS, the generated microwave signal can be
School of Opto-Electronic Engineering
专业英语文献汇报
5/30/2015
4
Results and Discussions
Nanjing University of Posts and Telecomunications
• As can be seen in fig(a) the resonance peak gets suppressed with the increasing of bias current from 15 mA to 90 mA. fig(b) shows the response curve of the DFB laser under optical injection with different injection ratio and detuning frequency Apparently, the resonance peak is enhanced and its tuning range is enlarged evidently by optical injection.
汇报人：
2015年5月20日
School of Opto-Electronic Engineering
专业英语文献汇报
5/30/2015
1
Abstract
Βιβλιοθήκη Baidu
Nanjing University of Posts and Telecomunications
A widely tunable OEO based on a directly modulated DFB semiconductor laser under optical injection is demonstrated. Microwave signals with frequency tuned from 5.98 to 15.22 GHz are generated. The phase noise of the generated 12.2 GHz microwave signal is measured to be -103.8 dBc/Hz at 10 kHz frequency offset.