The temperature dependence of spectral emission from semiconductor lasers showing long time delays

Some semiconductor lasers show long time delays when operated at a temperature above a characteristic critical value. This long time delay can only be explained in terms of a saturable absorption mechanism, and a recent model attributing this mechanism to the impurity band tails has successfully explained the kinetics and the current and temperature dependence of the delays. The model also predicts that the onset of long time delays is accompanied by a change in photon energy of the laser spectrum. Measurements of laser emission spectra over a range of temperatures have shown such changes in all our lasers with long time delays and this evidence validates the band tail saturable absorption model for long time delays.