High power low divergence angle SSC integrated 1.3 μm InGaAlAs/InP MQW DFB laser

Area of Science:

• Optoelectronics
• Semiconductor Lasers

Background:

• High-power semiconductor lasers are crucial for various applications.
• Existing designs often face limitations in beam quality and output power.

Purpose of the Study:

• To design and fabricate a novel high-power 1.3 μm InGaAlAs/InP multi-quantum well (MQW) distributed feedback (DFB) laser.
• To integrate a laterally tapered spot size converter (SSC) for improved beam characteristics.

Main Methods:

• Fabrication of a novel InGaAlAs/InP MQW DFB laser structure.
• Integration of a laterally tapered spot size converter (SSC).
• Inclusion of a ridge waveguide-free section after the SSC to reduce divergence.

Main Results:

• Measured far-field divergence angles below 10° in both lateral and vertical directions.
• Side mode suppression ratio (SMSR) exceeding 50 dB.
• Optical output power greater than 50 mW at 250 mA injection current and 50°C.

Conclusions:

• The novel MQW DFB laser with integrated SSC demonstrates excellent performance characteristics.
• The design effectively reduces beam divergence while maintaining high output power and SMSR.
• This laser is a promising candidate for applications requiring high-quality, high-power optical output.