利用PPKTP晶体倍频产生397．5nm激光的实验研究

397.5 nm Laser Produced by Resonant Frequency-doubling with PPKTP Crystal

使用周期性极化(PPKTP)晶体进行了795 nm激光倍频的实验研究。实验中,基频(795 nm)激光通过锥形放大器(TPA)实现了激光功率放大(400 mW),再经过光纤整形后功率输出达100 mW以上。将该激光单次通过PPKTP晶体,我们测量了倍频效率随晶体温度的变化关系。再将PPKTP晶体放入红外谐振倍频腔内,在最佳匹配温度和红外光共振条件下,获得了近14 mW的397.5 nm紫外光,倍频效率为13%。

Generation of 397. 5 nm laser is implemented in the optical with PPKTP crystal by means of frequency-doubling of 795 nm laser. In the experiment, the power of the fundamental wave at 795 nm is firstly amplified to 400 mW with the help of tapered amplifier （TPA）, and then it is injected into optical cavity after the propagation in the fiber where the mode of beam is improved and the output power of more than 100 mW is obtained. We measured the relationship between frequency doubling efficiency versus crystal temperature in the case of laser＇s single passing through the crystal. At last, under the condition of optical matching temperature and infrared resonance with the cavity mode, the second harmonic wave of 14 mW at 397.5 nm is produced in the optical cavity and the doubling efficiency equals to 13 %.