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

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Semiconductor Lasers

Background:

• High-power, narrow-linewidth lasers are crucial for applications like coherent optical networks, atomic clocks, and LiDAR.
• Existing technologies face challenges in simultaneously achieving high power and narrow linewidth.

Purpose of the Study:

• To demonstrate a novel hybrid integrated laser architecture combining a silicon-on-insulator (SOI) platform with a semiconductor optical amplifier (SOA).
• To achieve simultaneous high output power and narrow linewidth in a compact device.

Main Methods:

• Fabrication of a waveguide Bragg grating on a 3 µm thick-SOI platform.
• Integration with a semiconductor optical amplifier (SOA) gain chip.
• Utilizing a 6-mm-long DBR grating with a specific period (224 nm) and duty cycle (75%).

Main Results:

• Achieved an intrinsic linewidth of 4.89 kHz.
• Obtained ultra-sharp spectral filtering with a 30 pm FWHM.
• Delivered an output power of 112 mW while maintaining kHz-level linewidth.
• Demonstrated superior fiber-chip coupling and power handling due to the thick-SOI platform.

Conclusions:

• The developed hybrid integrated laser architecture offers a manufacturable solution for high-power, narrow-linewidth laser requirements.
• This technology enables advancements in coherent optical networks, optical atomic clocks, and LiDAR systems.
• The combination of thick-SOI and SOA provides a robust platform for future photonic integrated circuits.