采用基于一体化结构的环形倍频腔,比较了Hansch-Couillaud,Pound-Drever-Hall和内调制3种锁定方法,研究了不同倍频晶体长度和晶体内光束直径分布对倍频过程稳定性的影响。实验结果表明,一体化腔结构有效提高了抗干扰能力和稳定性;使用3种倍频腔锁定方法达到的倍频输出功率的稳定度为3%(其中基频光功率漂移为2%)。实验发现,由于晶体对倍频光的吸收,过长的晶体长度、过小的晶体内光束直径和不合适的光腰位置,可明显影响倍频光的最大倍频功率和稳定性。实验得到的最大461 nm蓝光倍频输出功率310 mW,倍频效率54.8%,净倍频效率71.3%。实验还比较了不同反射率输入耦合镜的耦合率。

This paper shows an external integrated ring cavity used to generate 461 nm blue radiation,which was locked by three different methods,Hansch-Couillaud,Pound-Drever-Hall,and intramodulation. And the factors the length of crystal and waist of fundamental light in crystal that affected the stability of output,were studied. The experimental results show that the integrated cavity improves the stability of output of 461 nm. And it reaches 3%,including 2% instability of fundamental. Because of absorption of 461 nm,long crystal,small waist and its disposition could impact their power and stability. And the output of second harmonic generation reaches 310 mW,54.8% of the conversion efficiency,and 71.3% of the net conversion efficiency. The reflection ratio of coupling mirror was discussed in addition.