Extraction-Controlled Quantum Cascade Lasers

TL;DR

This paper proposes a simplified two-well design for terahertz quantum cascade lasers that uses scattering injection and resonant tunneling for electron extraction, predicting operation above 200 K at 2.8 THz.

Contribution

The design introduces a novel extraction mechanism that also manages positive differential conductivity, analyzed through nonequilibrium Green functions.

Findings

Lasing predicted above 200 K at 2.8 THz

Efficient electron extraction via resonant tunneling

Design simplifies existing quantum cascade laser architectures

Abstract

A simple two-well design for terahertz quantum cascade lasers is proposed which is based on scattering injection and the efficient extraction of electrons from the lower laser level by resonant tunneling. In contrast to existing designs this extraction also controls the positive differential conductivity. The device is analyzed by calculations based on nonequilibrium Green functions, which predict lasing operation well above 200 K at a frequency of 2.8 THz.