Low-threshold 2 µm InAs/InP quantum dash lasers enabled by punctuated growth

Area of Science:

• Photonics and Optoelectronics
• Semiconductor Lasers
• Nanotechnology

Background:

• 2 µm photonics and optoelectronics are crucial for applications like optical communications, LiDAR, and chemical sensing.
• Development of Indium Phosphide (InP)-based 2 µm gain materials with 0D nanostructures has been limited.
• There is a growing need for efficient laser sources in the 2 µm wavelength range.

Purpose of the Study:

• To demonstrate low-threshold, continuous wave (CW) lasing at 2 µm using InAs quantum dash/InP lasers.
• To investigate the performance of these lasers under various operating conditions (SPW, QCW, CW).
• To assess the thermal stability of the developed laser devices.

Main Methods:

• Fabrication of ridge-waveguide lasers using InAs quantum dashes embedded in an InP matrix.
• Utilized a punctuated growth technique for the quantum structure.
• Characterized laser performance including threshold current density, lasing wavelength, and thermal stability (T0).

Main Results:

• Achieved low threshold current densities: 657 A/cm² (SPW), 1183 A/cm² (QCW), and 1944 A/cm² (CW) for 7.1 µm wide ridge-waveguide lasers.
• Demonstrated continuous wave lasing centered at 1.97 µm, consistent with photoluminescence studies.
• Observed good thermal stability with a characteristic temperature (T0) of 43 K under SPW mode.

Conclusions:

• The developed InAs quantum dash/InP lasers enable efficient 2 µm wavelength emission.
• The punctuated growth method is effective for creating high-performance 0D nanostructured gain materials.
• These lasers are a key enabling technology for future 2 µm optical communication and sensing systems.