Two-well quantum cascade laser optimization by non-equilibrium Green's function modelling

TL;DR

This paper models and experimentally validates a two-well quantum cascade laser operating at 192 K, using non-equilibrium Green's function simulations to optimize design and analyze high-temperature limitations.

Contribution

It introduces a non-equilibrium Green's function modeling approach for optimizing quantum cascade laser design and confirms the results through experimental fabrication and testing.

Findings

Laser operates up to 192 K

High-temperature lasing failure due to scattering and re-absorption

Modeling accurately predicts experimental outcomes

Abstract

We present a two-quantum well THz intersubband laser operating up to 192 K. The structure has been optimized with a non-equilibrium Green's function model. The result of this optimization was confirmed experimentally by growing, processing and measuring a number of proposed designs. At high temperature (T>200 K), the simulations indicate that lasing fails due to a combination of electron-electron scattering, thermal backfilling, and, most importantly, re-absorption coming from broadened states.