Fig. 1. Structural diagram and packaged product (inset) of hybrid integrated self-injection locked narrow-linewidth laser

Fig. 2. Laser frequency noise and linewidth test results at different optical feedback intensities. (a) Laser frequency noise power spectral density; (b) laser intrinsic linewidth, 1 ms integral linewidth,and delayed self-heterodyne linewidth

Fig. 3. Comparison of laser tuning ranges before and after optimization of optical feedback intensity. (a) When reflectivity of tunable mirror is 0; (b) when reflectivity of tunable mirror is 32%