Semiconductor lasers with ultra-low noise and narrow linewidth are crucial for advanced applications, including high-performance communication, optical sensing, and quantum metrology. In this work, we demonstrate a compact external cavity semiconductor laser that achieves high output power, narrow spectral linewidth, and low noise. We utilize carrier–photon interactions to establish an optical negative feedback between optical frequency and intensity and design an asymmetric reflectivity external cavity waveguide that optimizes the optical field distribution to suppress partial phase noise, thereby enabling additional noise reduction and linewidth narrowing. The spectral linewidth was compressed by three orders of magnitude to 2.05 kHz, the relative intensity noise was reduced to −164.2 dBc/Hz, the side mode suppression ratio reached 61.18 dB, and the output power peaked at 150.8 mW. Moreover, the proposed laser structure exhibits excellent spectral and power stability and offers significant advantages through reduced manufacturing cost and process complexity, thereby facilitating the further development and application of high-power, narrow-linewidth lasers.
Li et al. (Mon,) studied this question.