基于Pulser/Sustainer技术的可调谐长脉冲TE CO2激光器

采用光栅谐振腔,对一台基于Pulser/sustainer技术的紫外预电离长脉冲TE CO2激光器的调谐特性进行了实验研究.在增益体积为1.17 L,激光混合气体体积比V(CO2)∶V(N2)∶V(He)=1∶5∶19,工作气压为30 kPa条件下,实验测量了75条激光谱线的输出脉冲能量和脉冲宽度(半高全宽,FWHM),结果表明,相同的激励条件下,不同的激光波长,激光输出脉冲宽度有所不同.通过仔细观察比较四条主要谱线(9R(20),9P(20),10R(20),10P(20))的激光输出脉冲波形随放电电压、放电脉宽以及气体成分配比等的变化情况,说明基于pulser/sustainer技术激励的长脉冲可调谐TE CO2激光器的激光输出脉冲宽度随调谐波长的不同而变化.简单实验分析表明,谱线增益的变化可能是引起谱线输出脉冲宽度不同的主要原因.

Tunable Long Pulse TE CO2 Laser with Pulser/Sustainer Excitation

A grating tuned long pulse ultraviolet (UV)-preionized TE CO2 laser excited by pulser/sustainer discharge is demonstrated. With gas mixture volume fraction of V(CO2):V(N2):V(He)=1:5:19 and total gas pressure of 30 kPa, the laser output pulse energies and laser pulse widths (full-width at half-maximum, FWHM) of altogether 75 spectral lines are obtained. The measured results show that with the same pumping parameters the laser pulse width of each spectral line differs considerably as the grating is tuned from one line to another. Detailed measurement is carefully made on the laser output pulse widths of the four spectral lines 9R(20), 9P(20), 10R(20) and 10P(20) under different discharge voltage, discharge pulse width or gas mixture volume fraction, which strongly illustrate that the laser pulse width in a tunable long pulse TE CO2 laser with pulser/sustainer discharge varies with the output laser wavelength. By simultaneously measuring the discharge current waveform and the output laser pulse profile, it is found that the variation of the laser pulse width at each spectral line is perhaps mainly due to the gain difference of each spectral line.