Short‐wavelength InP quantum cascade laser sources by quasi‐phase‐matched intracavity second‐harmonic generation

Abstract

AbstractShort‐wavelength quantum cascade laser (QCL) sources, based on transversely integrated giant nonlinearity have been designed and fabricated. Devices consist of an injectorless GaInAs/AlInAs/InP pump QCL and a passive two‐well based nonlinearity grown on top of the pump active region. The nonlinearity was designed to possess a giant nonlinear response for the process of second‐harmonic generation (SHG). For efficient SHG process, the wave‐vector mismatch between the fundamental and the nonlinear signals was compensated by structuring the nonlinear layer into the 50% duty‐cycle quasi‐phase‐matching gratings. Using this approach we were able to demonstrate room‐temperature operation at 3.5 µm and 2.7 µm second‐harmonic emission wavelengths with output power levels up to 30 µW. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)