Wavelength tuning of GaAs/AlGaAs terahertz quantum cascade lasers by controlling aluminum content in barriers

We present an approach of uniformly changing the barrier height of AlGaAs in GaAs/AlGaAs based Terahertz (THz) quantum cascade laser structures for tuning the emission wavelengths. By uniformly changing the aluminum content of all the barriers from 15.5% to 13.5% - in a set of 5 MBE-grown samples - emission wavelengths from similar to 70 to 67.5 mu m, in nearly equal steps, are realized. (C) 2010 Elsevier B.V. All rights reserved.