COMPARISON OF LONG-TIME DELAY IN LASING IN HOMO-EPITAXIALLY AND HETEROEPITAXIALLY GROWN II-VI LASER-DIODES

Gain guided laser diodes exhibit unexpected low threshold current dens ities. Under these conditions, lasing only occurs under a current depe ndent long-time delay, which is three orders of magnitude larger than the time needed to reach population inversion. This effect is attribut ed to a thermally induced index guiding. The change in temperature of the quantum well region can be estimated using the shift in the wavele ngth of emission to be up to 70 K. As a further consequence, the thres hold current density can be reduced by a factor of 4 simply by changin g the pulse width of the applied current.