High linear polarization, narrow linewidth hybrid semiconductor laser with an external birefringence waveguide Bragg...

Area of Science:

• Photonics and Optical Engineering
• Semiconductor Lasers
• Fiber Optic Communications

Background:

• High-performance lasers are crucial for advanced optical communication systems.
• Existing laser technologies face limitations in polarization, linewidth, and noise performance.
• Hybrid laser architectures offer potential for improved characteristics.

Purpose of the Study:

• To demonstrate a novel hybrid laser combining a semiconductor gain chip and a high birefringence waveguide Bragg grating (WBG).
• To characterize the laser's performance, focusing on polarization, linewidth, and noise.
• To provide a high-performance light source for coherent light communication.

Main Methods:

• Fabrication of a hybrid laser integrating a semiconductor gain chip with a WBG.
• Experimental characterization of output power, single longitudinal mode operation, side mode suppression ratio (SMSR), and polarization extinction ratio (PER).
• Numerical analysis of linewidth suppression using adiabatic chirp theory.

Main Results:

• The hybrid laser operates in the C-band with a maximum output power of 8.07 mW.
• Single longitudinal mode operation was achieved up to 410 mA with SMSR > 50.2 dB and PER > 39.6 dB.
• A narrow linewidth of 4.15 kHz and low relative intensity noise (RIN) of <-155 dBc/Hz were demonstrated.

Conclusions:

• The developed hybrid laser exhibits excellent polarization characteristics and a narrow linewidth.
• The device offers a high-performance light source suitable for coherent optical communication.
• The combination of semiconductor gain and WBG is effective for achieving superior laser performance.