THEORETICAL AND EXPERIMENTAL INVESTIGATION FOR THE EFFECT OF STRAIN ON THE BELOW THRESHOLD OUTPUT OF InGaAsP DIODE LASERS

Abstract

The effect of strain (stress) on the below threshold output of InGaAsP diode lasers has been investigated theoretically and experimentally. The degree of polarization (DOP) and the polarization- resolved spectral output (PRSO) were obtained as a function of the external stress applied to the device. A correlation between the DOP and the peak of the PRSO as a function of the stress was found. This correlation suggests that below threshold, DOP can be used to measure the strain in the active region of lasers. A model based on a strain modified Shockley matrix for the band calculation and a strain modified dipole moment for the optical emission has been constructed to bridge the correlation between the DOP and PRSO.