脉冲激光器功率与能量换算.pdf

合集下载

1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。

Basic Considerations on Power and Pulse Energy for Pulsed Lasers

Pulsed lasers emit pulses with a certain energy content and at a certain repetition rate. In the following, the relation between peak power, average power, energy per pulse and repetition rate is displayed.

An important parameter of a pulsed laser is the pulse energy (how much energy one pulse contains). This is determined by the pulse repetition rate and the average power (i.e. how much pulses create the average power over one second). The respective formula is:

Average Power [W] = Pulse Energy [J] · Repetition Rate [Hz]

or, more generally formulated: Pulse Energy [J] · Number of pulses

Time interval [s]

Average Power [W] = Example I: A laser with an average power of 75 W and a 10 kHz repetition rate has the following pulse energy:

75 W

104 s -1 Pulse Energy = = 75 · 10-4 · Ws = 7.5 mJ

The peak power (how much peak power is reached within this pulse) is important information. This is determined by the pulse width. Assuming a rectangular pulse, the respective formulas are:

Pulse Energy [J]

Pulse Width [s]

Peak Power [W] = Average Power [W]

Repetition Rate [Hz] · Pulse Width [s]

Peak Power [W] =

Example II: A laser with a pulse energy of 7.5 mJ and a pulse width of 60 ns has the following peak power:

Peak Power = = 0.125 · 106 W = 125 kW 7.5 · 10-3 J

60 · 10-9 s If the given values are the average power of 75 W, the repetition rate of 10 kHz and the pulse width of 60 ns, the calculation would be as follows:

Peak Power = 75 W

104 s -1 · 60 · 10-9 s = 1.25 · 105W = 125 kW

Disclaimer

This article does not attempt to cover all aspects of laser beams. All references and numbers are typical. Scientific literature dealing with these aspects is readily available. A list of articles and books can be provided upon request.