Current dependence of pulsations in semiconductor lasers due to photon induced modulation of optical loss

Pulsations in semiconductor lasers are frequently observed to occur within a range of injection currents above threshold. A model is proposed to account for the existence of the current range and attributes it to a critical optical power level at which photon induced modulation of optical loss takes place, such as due to the effect of self-focusing or lateral mode deformation. This value is estimated to be
0.36 \times 10^{15}
photons- cm
^-3
for double heterostructure oxide-striped lasers.