Opt Lett. 2019 Mar 1;44(5):1150-1153. doi: 10.1364/OL.44.001150.
To extend the coherence of quantum transitions for laser locking, as well as increase the compactness and stability of the experimental setup, we propose to utilize photonic integrated resonators with high second-harmonic (SH) generation efficiencies as reliable frequency doublers that link the desired frequencies with the frequency references. In this Letter, a sufficiently strong SH signal up to microwatts was generated by a photonic integrated frequency doubler using a milliwatt infrared (IR) laser source. Furthermore, an increased SH generation bandwidth covering Rb85 and Rb87D transition lines, as well as saturated absorption spectroscopy, was demonstrated by tuning the pump power and chip temperature. Here we present, to the best of our knowledge, the first successful locking of an IR laser to Rb saturated absorption lines via a photonic chip frequency doubler.
为了延长激光锁定的量子跃迁相干时间，并提高实验装置的紧凑性和稳定性，我们建议利用具有高二次谐波（SH）产生效率的光子集成谐振器作为可靠的倍频器，将所需频率与频率参考连接起来。在这封信件中，使用兆瓦级红外（IR）激光源，通过光子集成倍频器产生了足够强的微瓦级 SH 信号。此外，通过调节泵浦功率和芯片温度，实现了 SH 产生带宽的增加，涵盖了 Rb85 和 Rb87D 跃迁线，以及饱和吸收光谱。在这里，我们在已知范围内首次成功地通过光子芯片倍频器将 IR 激光锁定到 Rb 饱和吸收线上。
