Silica/Polymer TIR Optical Switches and a Proposal for Nonblocking Four-Port Routers

We have fabricated a wavelength-insensitive silica/polymer total-internal-reflection thermooptic switch element using photolithography and wet etching techniques. A switching power of 70 mW is required to drop the crosstalk below -20 dB. Under through and reflection states, the propagation losses of the 0.47-cm long core switch element are measured to be 1.8 and 3.6 dB, respectively. The 10%-90% rise time and the 90%-10% fall time are 0.35/0.38 and 0.52 ms, respectively. Using 11 switch elements, we have proposed a nonblocking four-port optical router. The propagation loss range is ~5.4-23.4 dB along all routing paths. Both the switch and the router show potential applications of wideband signal switching and routing in multiprocessor-based optical networks-on-chip.