Jongseok Kim

Variation of polarization tilt in GaInP/AlGaInP visible laser diodes

The dependence of polarization angle to the quantum well structural parameters and measurement conditions is investigated for GaInP/AlGaInP index-guided laser diodes. The laser diodes that have been studied are 635, 650 and 670 nm band laser diodes with strained quantum well active regions. It has been found that the polarization of radiation along (0 1 -1) direction varies by several degrees from ordinary TE/TM mode determined by the growth direction. The polarization tilt varies with respect to the strain and misorientation of the substrates. The polarization tilt seems to result from the birefringence in the asymmetric crystal structure induced by the strain of GaInP quantum well and the substrate misorientation toward [0 1 1].