具有热补偿的内腔KTP光参量振荡器

Intra-Cavity KTP Optical Parametric Oscillator With the Thermal Compensation

在电光调QNd:YAG激光抽运内腔KTP光参量振荡器中,由于在抽运光的谐振腔内插入了起偏器,当工作在高重复频率时,Nd:YAG棒热致双折射效应致使起偏器产生退偏损耗,导致抽运光能量下降和光束质量变差,最终光参量振荡器的激光输出能量也将下降。为了补偿热致双折射引起的起偏器退偏损耗,提出了基于λ/4波片的具有热补偿的内腔光参量振荡器结构,实验结果表明在高重复频率工作时,具有热补偿的内腔光参量振荡器较无补偿内腔光参量振荡器的激光输出能量提高了20%左右。

In the pumping laser cavity of the intra-cavity KTP optical parametric oscillator （OPO） pumped by the electrooptical-switched Nd：YAG laser, a polarmeter is plugged. When OPO works at high repetition rate frequency, the polarizer will produce depolarization losses because of the thermally induced birefringence in Nd：YAG rod. As a result the pumping laser energy will decrease and the laser beam quality will become worse. OPO output laser energy will fall. To compensae the depolarization losses induced by birefringence, a λ/4 wavelength plate is plugged in the pumping laser cavity. The experimental results show that the output laser energy of OPO with the thermal compensation excesses 20% to that without thermal compensation at high repetition rate frequency.