Towards Interband Cascade lasers on InP Substrate

Area of Science:

• Materials Science
• Optoelectronics
• Quantum Engineering

Background:

• Interband cascade lasers (ICLs) are crucial for mid-infrared (MIR) applications.
• Current ICL growth often relies on GaSb or InAs substrates, limiting cost-effectiveness and material quality.
• Developing ICLs on InP substrates is highly desirable for mature epitaxial technology.

Purpose of the Study:

• To propose and theoretically investigate novel interband cascade laser (ICL) active region designs.
• To achieve emission in the mid-infrared (MIR) spectral range using InP substrates.
• To leverage InP's mature epitaxial technology for cost-effective, high-quality ICL fabrication.

Main Methods:

• Theoretical investigation of type II, "W"-shaped quantum wells (InGaAs/InAs/GaAsSb).
• Utilizing the 8-band k·p approximation to calculate band structure.
• Exploring various barrier compositions to manage strain levels.

Main Results:

• Inclusion of a thin InAs layer provided additional tuning for electronic states and optical transitions.
• Achieved tunable emission wavelengths from 3 μm to 4.6 μm.
• Demonstrated competitive gain and tunable oscillator strength, comparable to state-of-the-art ICLs.

Conclusions:

• The proposed InP-based ICL designs offer a promising, cost-effective solution for MIR applications.
• The tunable "W"-shaped quantum wells enable precise control over emission characteristics.
• This work paves the way for practical, InP-based ICLs, particularly for optical gas sensing.