Abstract
We present a simple yet powerful technique to measure and stabilize the relative frequency noise between two lasers emitting at vastly different wavelengths. The noise of each laser is extracted simultaneously by a frequency discriminator built around an unstabilized Mach–Zehnder fiber interferometer. Our protocol ensures that the instability of the interferometer is canceled and yields a direct measure of the relative noise between the lasers. As a demonstration, we measure the noise of a 895 nm diode laser against a reference laser located hundreds of nm away at 1561 nm. We also demonstrate the ability to stabilize the two lasers with a control bandwidth of 100 kHz using a Red Pitaya and reach a sensitivity of $1 \;{\rm{H}}{{\rm{z}}^2}/{\rm{Hz}}$ limited by detector noise. We independently verify the performance using a commercial frequency comb. This approach stands as a simple and cheap alternative to frequency combs to transport frequency stability across large spectral intervals or to characterize the noise of arbitrary color sources.
© 2020 Optical Society of America
Full Article | PDF ArticleMore Like This
Qian Zhang, Yubin Hou, Xi Wang, Weihua Song, Xu Chen, Wu Bin, Ju Li, Chunnong Zhao, and Pu Wang
Opt. Lett. 45(17) 4911-4914 (2020)
Tomohiro Tetsumoto, Fumiya Ayano, Mark Yeo, Julian Webber, Tadao Nagatsuma, and Antoine Rolland
Opt. Lett. 45(16) 4377-4380 (2020)
Vincent Michaud-Belleau, Mark Charlet, Alex Tourigny-Plante, Jean-Daniel Deschênes, and Jérôme Genest
Opt. Lett. 45(3) 670-673 (2020)