Self-mixing signals in terahertz lasers

Abstract

Recently demonstrated self-mixing effect in terahertz quantum cascade lasers (QCL) opens new possibilities for detectorless sensing in this range of electromagnetic spectrum. In this paper we compare self-mixing signals obtained from variations in QCL terminal voltage against the signals obtained from variations in QCL radiated power monitored using a bolometer. We show that these two signals are equivalent allowing for the disposal of a conventional bulky and slow thermal detector.