Analysis of phase-matching conditions for internal second-harmonic generation in InGaAs quantum well laser diodes

Abstract

In this paper we present an analysis of the phase-matching conditions for internal second-harmonic generation in InGaAs quantum-well laser diodes in order to enhance the conversion efficiency. We have characterized the role of phase- mismatching in the spectral distribution of the internal second-harmonic generation in the CW operation of these lasers. The emission of pairs of narrow blue-green peaks having perfectly symmetrical spectral positions with respect to the central peak of pure second-harmonic generation at approximately 480 nm is most probably enhanced by a mechanism of reciprocal cancellation of the respective phase-mismatch vectors. This study is important for the assessment of the relationship between the structural parameters of the laser and the conditions which contribute to the stimulation of second-order optical nonlinearities in the laser active region.