Interband cascade lasers grown simultaneously on GaSb, GaAs and Si substrates.

Area of Science:

• Semiconductor Lasers
• Optoelectronics
• Materials Science

Background:

• Interband cascade lasers (ICLs) are crucial for mid-infrared applications.
• Heteroepitaxial growth on mismatched substrates like GaAs and Si presents challenges due to dislocations.
• Developing ICLs on cost-effective substrates is highly desirable.

Purpose of the Study:

• To investigate the performance of Sb-based ICLs grown on GaSb, GaAs, and Si substrates.
• To assess the continuous-wave (CW) operation capabilities and thermal stability of these devices.
• To evaluate the tolerance of ICLs to dislocations when grown on mismatched substrates.

Main Methods:

• Simultaneous growth of Sb-based ICLs on GaSb, GaAs, and Si substrates.
• Characterization of threshold currents and CW operation temperatures.
• Measurement of output power at 3.3 µm.
• Accelerated aging tests at elevated temperatures and high injection currents.

Main Results:

• Devices on all substrates showed similar threshold currents (~40 mA at 20°C).
• CW operation was achieved up to 65°C on GaSb, GaAs, and Si, despite high dislocation densities (~4.10^8 cm^-2) on mismatched substrates.
• Output power exceeded 30 mW/facet at 20°C for devices emitting at 3.3 µm.
• No degradation was observed after 500 hours of CW operation at 50°C with five times the threshold current for ICLs on GaAs and Si.

Conclusions:

• Sb-based ICLs exhibit high performance and excellent operational stability on GaSb, GaAs, and Si.
• These ICLs demonstrate significant tolerance to dislocations, enabling their growth on mismatched, cost-effective substrates.
• The findings pave the way for practical applications of ICLs on silicon and GaAs platforms.