Current‐controlled wavelength tunability of a quantum cascade laser

Abstract

We report quantum cascade lasers (QCLs) which exhibit multiple peak structures in the emission spectra as a function of injected current, and provide the availability of additional laser lines in the single QCL. The emission spectra of quantum cascade lasers measured with varying current show emission wavelength peaks, separated by 110 nm, indicating the possibility of broad tuning range. The optical output power.vs. injected current curves also exhibit two separate thresholds at low duty cycles, indicating two different lasing conditions originating from the different transition levels. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)