THEORY OF DEFECT-INDUCED PULSATIONS IN SEMICONDUCTOR INJECTION-LASERS

The size of defects necessary to cause pulsations in otherwise ideal semiconductor injection lasers is calculated for two defect models: a nonradiative region and a number of nonradiative surfaces. The minimum length of the nonradiative region and the minimum number of nonradiative surfaces necessary to cause pulsations are determined. A comparison of these two results shows that in causing pulsations a nonradiative surface is roughly equivalent to a nonradiative region 0. 5 mu m in length. The critical sizes for pulsations are determined by solving the linearized coupled equations that describe damped relaxation oscillations about the steady state and determining the length of the region (or number of surfaces) necessary for damping to change into growth.