%0 Journal Article %J Optics Express %D 2015 %T Dense dissimilar waveguide routing for highly efficient thermo-optic switches on silicon %A Murray, Kyle %A Lu, Zeqin %A Jayatilleka, Hasitha %A Chrostowski, Lukas %U https://www.osapublishing.org/oe/abstract.cfm?uri=oe-23-15-19575 %X We analyze and demonstrate a method for increasing the efficiency of thermo-optic phase shifters on a silicon-on-insulator platform. The lack of cross-coupling between dissimilar waveguides allows highly dense waveguide routing under heating elements and a corresponding increase in efficiency. We demonstrate a device with highly dense routing of 9 waveguides under a 10 m wide heater and achieve a low switching power of 95 W, extinction ratio greater than 20 dB, and less than 0.1 dB ripple in the through spectrum with a footprint of less than 800 m 180 m. The increase in waveguide density is found not to negatively impact the switch response time. %8 07/2015