Abstract
We demonstrate an electro-thermally tunable phase-shift in a slow-light Bragg reflector waveguide with large waveguide dispersion. The group index and phase shift are measured from the interference fringe between the reflection of input light and the output light in a 20-mu m-long slow light waveguide. An electro-thermally tunable phase shift is over pi in a compact 20-mu m-long waveguide with power consumption below 30 mW. The result shows the low polarization dependence of the phase shift owing to the low polarization dependent group index of the slow-light Bragg reflector waveguide. (C) 2014 The Japan Society of Applied Physics