Semiconductor laser with curved deep-etched distributed Bragg reflectors supporting a planar Gaussian mode

Area of Science:

• Semiconductor lasers
• Integrated optics
• Photonics

Background:

• Semiconductor lasers are crucial for optical communications and integrated photonic circuits.
• Achieving a stable, fundamental Gaussian mode in compact lasers is essential for high-performance applications.
• Distributed Bragg reflectors (DBRs) are commonly used for optical feedback in semiconductor lasers.

Purpose of the Study:

• To demonstrate a compact, integration-compatible semiconductor laser.
• To achieve stable planar Gaussian mode operation.
• To investigate the laser's performance characteristics, including threshold current and mode stability.

Main Methods:

• Fabrication of a compact semiconductor laser structure.
• Integration of curved deep-etched distributed Bragg reflectors (DBRs) for optical feedback.
• Characterization of laser performance, including threshold current and mode behavior at varying currents.

Main Results:

• Demonstration of a compact semiconductor laser supporting a planar Gaussian mode.
• Achieved a low threshold current of 10 mA for a 90-microm-long laser with a 2-microm waist.
• Observed stable Gaussian mode operation up to 1.7 times the threshold current.

Conclusions:

• The demonstrated laser design enables compact, integration-compatible devices with stable Gaussian mode operation.
• Curved DBRs effectively provide feedback for planar Gaussian modes.
• Spatial hole burning limits high-power operation, indicating areas for future optimization.