POLARIZATION OF THE SPONTANEOUS RADIATION OF STRESSED LASER HETEROSTRUCTURES

Measurement system with a rotating polaroid was constructed allowing t o detect the degree of the light polarization (rho) of 0.1% rho as a f unction of driving current (I) and axial stress (sigma) was studied fo r spontaneous output of the AlGaAs lasers at low pumping levels. It wa s found that in the range of sufficiently small currents rho linearly depends on I and sigma. When extrapolated to I = 0, rho depends not on ly on sigma, but also on the light amplification parameters of the ind ividual laser structure. These observations must be taken into account when one attempts to estimate the strain in the active layer of a dio de laser through the polarization measurements. The Cassidy's one-dime nsional model of the polarization effects in diode lasers was modified to include modulation of the optical absorption by the stimulated emi ssion in the active region at very low pumping intensities.