Galland N, Lučić N, Zhang S, Alvarez-Martinez H, Le Targat R, Ferrier A, Goldner P, Fang B, Seidelin S, Le Coq Y
Opt Lett. 2020 Apr 1;45(7):1930-1933. doi: 10.1364/OL.389833.
We present an experimental technique for realizing a specific absorption spectral pattern in a rare-earth-doped crystal at cryogenic temperatures. This pattern is subsequently probed on two spectral channels simultaneously, thereby producing an error signal allowing frequency locking of a laser on the said spectral pattern. Appropriate combination of the two channels leads to a substantial reduction in detection noise, paving the way to realizing an ultra-stable laser for which the detection noise can be made arbitrarily low when using multiple channels. We use this technique to realize a laser with a frequency instability of $ 1.7 \times 1{0^{{\bf - }15}} $1.7×10 at 1 s, not limited by the detection noise but by environmental perturbation of the crystal. This is comparable with the lowest instability demonstrated at 1 s to date for rare-earth-doped crystal stabilized lasers.
我们展示了一种用于在低温下在稀土掺杂晶体中实现特定吸收光谱图案的实验技术。随后在两个光谱通道上同时探测该图案，从而产生一个误差信号，使激光器能够锁定在所述光谱图案上。两个通道的适当组合可大幅降低检测噪声，为实现超稳定激光器铺平了道路，当使用多个通道时，检测噪声可被任意降低。我们使用该技术实现了一台激光器，其在1秒时的频率不稳定度为(1.7×10^{-15})，不受检测噪声限制，而是受晶体环境扰动限制。这与迄今为止在1秒时稀土掺杂晶体稳定激光器所展示的最低不稳定度相当。
