Compact thermally tunable silicon wavelength switch: Modeling and characterization

A wavelength-selective photonic switch is developed based on a Si microring resonator using thermooptic effect. The 10-mu m-diameter microring resonator uses single-mode strip Si waveguides of dimension 0.25 mu m x 0.45 mu m operating at 1.5 mu m. Full-width at half-maximum are in the range 0.14.2 nm. The ultrawide tunable range (> 6.4 nm) and wide free spectral range (similar to 18 nm) of the switch element enables wavelength reconfigurable multichannel matrix switch by wavelength multiplexing/demultiplexing. Average rise delay time of 14 mu s with low switching power of 3.15 mW has been achieved with 0.2-nm wavelength tuning and 78 mu s, 104 mW for 6.4-nm tuning. Fall delay times are usually less than 10 mu s. Thermal simulations show 10%-20% agreement with the measurements up to 3.2-nm tuning. The compact size of the switch shows its potential as an active element in photonic integrated circuits.