Lewoczko-Adamczyk Wojciech, Pyrlik Christoph, Häger Johannes, Schwertfeger Sven, Wicht Andreas, Peters Achim, Erbert Götz, Tränkle Günther
Opt Express. 2015 Apr 20;23(8):9705-9. doi: 10.1364/OE.23.009705.
We present a compact, ultra-narrow-linewidth semiconductor laser based on a 780 nm distributed feedback diode laser optically self-locked to a mode of an external monolithic confocal Fabry-Perot resonator. We characterize spectral properties of the laser by measuring its frequency noise power spectral density. The white frequency noise levels at 5 Hz(2)/Hz above a Fourier frequency as small as 20 kHz. This noise level is more than five orders of magnitude smaller than the noise level of the same solitary diode laser without resonant optical feedback, and it is three orders of magnitude smaller than the noise level of a narrow linewidth, grating-based, extended-cavity diode laser. The corresponding Lorentzian linewidth of the laser with resonant optical feedback is 15.7 Hz at an output power exceeding 50 mW.
我们展示了一种基于780nm分布反馈二极管激光器的紧凑型、超窄线宽半导体激光器，该激光器通过光学方式自锁到外部单片共焦法布里-珀罗谐振器的一个模式上。我们通过测量其频率噪声功率谱密度来表征该激光器的光谱特性。在高达20kHz的傅里叶频率之上，5Hz(2)/Hz处的白频率噪声水平很低。该噪声水平比没有谐振光反馈的相同孤立二极管激光器的噪声水平小五个数量级以上，并且比基于光栅的窄线宽扩展腔二极管激光器的噪声水平小三个数量级。在输出功率超过50mW时，具有谐振光反馈的激光器的相应洛伦兹线宽为15.7Hz。
