Dual-lasing channel quantum cascade laser based on scattering-assisted injection design.

Area of Science:

• Semiconductor Physics
• Quantum Electronics
• Terahertz Technology

Background:

• Terahertz Quantum Cascade Lasers (THz QCLs) are crucial for various applications.
• Improving performance metrics like threshold current density and operating temperature is essential for practical THz QCLs.
• Scattering-assisted (SA) structures offer a pathway to enhance THz QCL performance.

Purpose of the Study:

• To demonstrate a dual lasing channel THz QCL using the GaAs/Al_0.17Ga_0.83As material system.
• To investigate the dual lasing channel operation theoretically and experimentally.
• To establish a design strategy for high-temperature, wide-frequency coverage THz QCLs.

Main Methods:

• Fabrication of a dual lasing channel THz QCL based on GaAs/Al_0.17Ga_0.83As.
• Experimental characterization of the THz QCL's lasing properties.
• Theoretical modeling of the dual lasing channel operation.

Main Results:

• Achieved the lowest reported threshold current density (550A/cm² at 50K) for GaAs/Al_xGa_1-xAs SA structures.
• Demonstrated operation up to a maximum lasing temperature of 144K.
• Confirmed dual lasing channel operation through theoretical and experimental investigations.

Conclusions:

• The developed THz QCL exhibits excellent low-frequency emission, dual lasing channel capability, low threshold current density, and high-temperature performance.
• These devices are ideal for low-frequency applications.
• The findings provide a design strategy for future high-performance THz QCLs with broad frequency coverage.