2024/03/19 by Jiajun Wu, Wu, Jiajun, Shan Zhong +3
Engineering · Physics and Astronomy · #Photonic and Optical Devices #Semiconductor Lasers and Optical Devices #Advanced Fiber Laser Technologies
paper · pdf · doi:10.48550/arxiv.2404.04266
The optical feedback intensity is an important parameter for realizing narrow linewidth lasers in Whispering-gallery-mode resonator (WGMR) self-injection locking technology. We proposed an approach that enhances the intensity of intracavity feedback in crystalline WGMR by using only a single coated auxiliary prism. Compared to the Rayleigh scattering, the feedback intensity of the enhanced scheme increased by more than a hundred times. Furthermore, we demonstrated that, with the enhanced approach, the instantaneous linewidth of the laser was suppressed to 7 Hz level, the locking range was expanded up to 8 GHz, and the relative intensity noise (RIN) was reduced to -152 dBc/Hz@10MHz. The feedback enhanced design is compact, easy-to-operated and can be integrated with the WGMR. It provides a miniaturized solution for controlling optical feedback intensity in WGMR self-injection locking technology.