High-power narrow spectrum GaSb-based DBR lasers emitting near 2.1  µm

Area of Science:

• Semiconductor diode lasers
• Optoelectronics
• Materials science

Background:

• GaSb-based diode lasers are crucial for various applications.
• Achieving stable high-power, narrow-linewidth operation remains a challenge.
• Distributed Bragg reflector (DBR) mirrors offer wavelength selectivity.

Purpose of the Study:

• To demonstrate stable high-power, narrow-linewidth operation of GaSb-based diode lasers.
• To investigate the effectiveness of sixth-order surface-etched DBR mirrors.
• To analyze laser performance characteristics, including output power and spectral properties.

Main Methods:

• Fabrication of GaSb-based diode lasers with 100 µm wide ridge waveguides.
• Integration of sixth-order surface-etched distributed Bragg reflector (DBR) mirrors.
• Characterization of laser performance in continuous wave (CW) regime at various operating currents and temperatures.

Main Results:

• Stable high-power (∼850 mW) narrow-linewidth operation achieved.
• Continuous wave (CW) output power limited by thermal rollover.
• Laser emission spectrum consistently defined by DBR reflectivity across a wide temperature range.
• Operation observed at DBR line with detuning from gain peak exceeding 10 meV.

Conclusions:

• Sixth-order surface-etched DBR mirrors enable stable high-power, narrow-linewidth operation in GaSb-based diode lasers.
• The DBR mirrors effectively control the laser emission spectrum, even under detuning conditions.
• These devices show promise for applications demanding precise wavelength control and high output power.