High-Temperature Operating Narrow-Period Terahertz Quantum Cascade Laser Designs

Abstract

Presently, terahertz quantum cascade lasers still suffer from operations below room temperature, which prohibits extensive applications in terahertz spectra. The past continuous contributions to improving the operating temperatures were by clarifying the main thermal degradation process and proposing different designs with the optical gain demonstrating higher temperature cut-offs. Recent designs have attempted to employ a narrow period length with a simplified and clean state system, and reach renewed operating temperatures above 200 K. This study reveals how historic designs approach such narrow-period designs, discus the limitations within those designs, and show further possible designs for higher operating temperatures.

Longitudinal optical (LO) and LO-like phonon resonant mid-infrared radiation emission and absorption by surface micro-structures on III-nitrides

“…Quantum cascade lasers (QCLs) 1 and resonant tunneling diodes 2 are examples of devices based on electronic energy systems. As the radiation emitted from electronic systems displays a significant increase in linewidth with increasing temperature, device cooling becomes essential for most operation of QCLs in the THz frequency region 3 . The interaction between electrons and longitudinal optical (LO) phonons is a crucial factor limiting the emission efficiency.…”