Разработка двухсекционного квантово-каскадного лазера для задач терагерцовой спектроскопии

Abstract

This paper presents studies of a two-section THz quantum-cascade laser (QCL) consisting of 4 tunnel-coupled quantum wells (QWs) GaAs/Al0.15Ga0.85As with a resonant-phonon depopulation scheme. The QCL is based on a double metal waveguide with a total length of 2 mm, in which an air gap 3 μm wide is formed by plasma-chemical etching. This makes it possible to form two optically coupled sections, an active section with a length L1 = 1.8 mm and a passive section with a length L2 from 200 to 300 μm (see Fig. 1). Based on the study of the emission spectra of a two-section laser, it was found that the laser, when the temperature/current changes at certain operating points, changes from one emission mode to multimode emission. For further analysis of the behavior of the laser, a map of operating modes was built (see Fig. 2).