On-chip quasi-digital optical switch using silicon microring resonator-coupled Mach-Zehnder interferometer

In this work, we demonstrate thermo-optical quasi-digital optical switch (q-DOS) using silicon microring resonator-coupled Mach-Zehnder interferometer. The optical transmission spectra show box-like response with 1-dB and 3-dB bandwidths of similar to 1.3 nm and similar to 1.6 nm, respectively. Such broadband flat-top optical response improves the tolerance to the light source wavelength fluctuation of +/- 6 and temperature variation of +/- 6 degrees C. Dynamic characterizations show the device with switching power of similar to 7 mW, switching time of similar to 7 mu s, and on/ off ratio of > 30 dB. For performance comparison, we also demonstrate a carrier injection-based electro-optical qDOS by integrating lateral P-i-N junction with the microring resonator, which significantly reduces power consumption to similar to 12 mW and switching time to similar to 0.7 ns only. (C)2013 Optical Society of America