Observation of WDM Crosstalk in Passive Semiconductor Waveguides

We show that passive InP-InGaAsP waveguides exhibit high non- linear loss due to the highly energetic carriers generated by two-photon absorption. We have further demonstrated, for the first time, that due to this effect, severe crosstalk occurs between wavelength channels when they are transmitted through a semiconductor waveguide operated in the transparency region, at power levels used in typical WDM systems. Some solutions are proposed.