PARAMETRIC ANALYSIS OF SEMICONDUCTOR-DOPED CLASSES FOR ALL-OPTICAL SWITCHING

We use the basic physical parameters of semiconductor-doped glasses (S DG's) to compute the dependence of their nonlinear index n(2) due to t he bandgap resonant effect on pump intensity and to predict the power and length requirements of an all-optical SDG waveguide switch, The ma in conclusions are that 1) the pump and signal wavelengths should be i n specific and different ranges to minimize the switching power and si gnal loss, 2) for CdSSe- and CdTe-doped glasses, n(2) is relatively sm all, 3) their power requirements are consequently quite high (2-100 W) , although 4) much lower than in a comparable device operated near the half-bandgap, We provide evidence that this weak nonlinearity, compar ed to that of semiconductors in bulk, is due to the strong nonradiativ e recombination of carriers arising from the small size of the semicon ductor microcrystallites. Projections indicate a reduction in switchin g power by up to a factor of 1000 by increasing the microcrystallite s ize, thus producing a slower (ns) but more power efficient switch.