High-power kHz-level linewidth hybrid integrated diode laser based on thick-SOI waveguide

We demonstrate a single-mode hybrid integrated laser architecture combining a waveguide Bragg grating fabricated on a 3 µm silicon-on-insulator (SOI) platform with a semiconductor optical amplifier (SOA) gain chip. Utilizing a Bragg grating with a controlled period of 224 nm, and duty cycle of 75%, the device achieves a narrow intrinsic linewidth of 4.89 kHz. With a compact 6-mm-long DBR grating, this design simultaneously yields an ultra-sharp spectral filtering with the full width at half maximum value of 30 pm and a low coupling constant of 0.68 cm^-1. Leveraging the thick-SOI platform's advantages-including superior fiber-chip coupling efficiency and enhanced power handling capabilities - in conjunction with a high-power SOA design, the system delivers output power of 112 mW while maintaining kHz-level linewidth. This performance-optimized design establishes a manufacturable pathway for implementing high-power narrow-linewidth lasers in coherent optical networks, optical atomic clocks, and light detection and ranging (LiDAR) systems that require simultaneous high coherence and high-power output.