%0 Journal Article %J IEEE Photonics Technology Letters %D 2015 %T Michelson Interferometer Thermo-optic Switch on SOI with a 50 Microwatt Power Consumption %A Lu, Zeqin %A Murray, Kyle %A Jayatilleka, Hasitha %A Chrostowski, Lukas %U http://dx.doi.org/10.1109/LPT.2015.2462341 %X We demonstrate photonic ultra-efficient thermooptic switches on a 220 nm silicon-on-insulator (SOI) platform. We used several approaches to increase the tuning efficiency of the switches. We used folded waveguides in a Michelson interferometer configuration to increase the optical interaction length of the light with the heated region, and used a suspended structure to improve thermal isolation. An ultra-low switching power of 50 uW is realized with an extinction ratio of over 26 dB for the transverse electric (TE) mode at 1550 nm. The 10%-90% response time of the switch is 1.28 ms, including a 780 us rise time and a 500 us fall time. As compared to the best thermooptic switch in the literature, our device shows approximately an order of magnitude reduction in power consumption. %8 07/2015