Vainio Markku, Halonen Lauri
Opt Lett. 2017 Jul 15;42(14):2722-2725. doi: 10.1364/OL.42.002722.
A synchronously pumped optical parametric oscillator (SP-OPO) is one of the most common techniques to generate femtosecond frequency combs in the mid-infrared region. Stable long-term operation of an SP-OPO requires active locking of the OPO resonator round-trip time to the pump pulse interval. A simple modulation-free locking method based on stabilization of narrow-band frequency-doubled power of the SP-OPO output comb is demonstrated in this Letter. The method relies on the strong dependency of frequency-doubled power on spectral shape of the comb, leading to better stability of the comb envelope spectrum than the commonly used dither-and-lock method.
同步泵浦光学参量振荡器（SP - OPO）是在中红外区域产生飞秒频率梳的最常用技术之一。SP - OPO的稳定长期运行需要将OPO谐振器的往返时间主动锁定到泵浦脉冲间隔。本文展示了一种基于稳定SP - OPO输出梳的窄带倍频功率的简单无调制锁定方法。该方法依赖于倍频功率对频率梳频谱形状的强烈依赖性，从而使频率梳包络谱比常用的抖动锁定方法具有更好的稳定性。
