Nd∶YVO_4激光回馈干涉仪

Nd ∶ YVO_4 laser feedback interferometer

目前研制的Nd∶YAG激光回馈干涉仪的激光器偏振态易发生变化。与Nd∶YAG晶体相比,Nd∶YVO4晶体输出的单纵模线偏振光更稳定,弛豫振荡的中心频率更高,从而增大移频频率,提高测速精度。因此设计制作了Nd∶YVO4激光回馈干涉仪样机,并采用具有外触发功能的数字相位计,经过激光器功率稳定性实验和比对实验,得到激光回馈干涉仪样机目前的指标:激光器3 h内的功率变动值为1.89%,干涉仪400 mm测量范围内的线性度为7.0625×10-6,标准差为0.936μm。

At present,laser polarization state of Nd ： YAG laser feedback interferometer is easy to change. Compared with Nd ： YAG crystal, a single longitudinal mode linearly polarized light of Nd ： YVO4 crystal is more stable, and the center frequency of relaxation oscillation is higher, thus velocity measurement accuracy increases with the increase of shift frequency. Nd ： YVO4 laser feedback interferometer prototype is designed and manufactured, and a digital phase meter with external trigger function is used. After the optical power stability experiment and comparative experiment, the indexes of the laser feedback interferometer are obtained. The laser power fluctuation is 1.89% within 3 h, lineari- ty is 7.0625 × 10-6 within the 400 mm measuring range and standard deviation is 0. 936 μm.