InGaAs/AlInGaAs THz Quantum Cascade Lasers operating up to 195 K in strong magnetic field

TL;DR

This paper reports on InGaAs/AlInGaAs THz quantum cascade lasers that operate up to 195 K under strong magnetic fields, demonstrating enhanced performance and new emission features through magneto-spectroscopic analysis.

Contribution

It presents a detailed magneto-spectroscopic study of InGaAs/AlInGaAs THz QCLs, achieving record operation temperature of 195 K in magnetic fields, and compares emission and transport data for different waveguides.

Findings

Maximum operation temperature of 195 K at 12 T magnetic field.

Detection of additional lasing at 5.9 meV in specific magnetic field range.

Enhanced confinement and emission properties under strong magnetic fields.

Abstract

Terahertz quantum cascade lasers based on InGaAs wells and quaternary AlInGaAs barriers were measured in magnetic field. This study was carried out on a four quantum well active region design with photon energy of 14.3 meV processed both with Au and Cu waveguides. The heterostructure operates up to 148 K at B=0 T and in a Cu waveguide. The complete magneto-spectroscopic study allowed the comparison of emission and transport data. Increasing the magnetic field, the low effective mass of the InGaAs wells allowed us to reach the very strong confinement regime. At B=12 T, where the cyclotron transition is almost resonant with the LO-phonon, we recorded a maximum operating temperature of 195 K for the devices with Cu waveguide. Additional lasing at 5.9 meV was detected for magnetic fields between 7.3 and 7.7 T.