Largely-tunable wideband Bragg gratings fabricated on SOI rib waveguides employed by deep-RIE

A largely-tunable wideband Bragg grating on a silicon-on-insulator (SOI) rib waveguide loaded with Au/Cr heater is presented. A deep first-order Bragg grating with smooth etched side wall has been successfully etched by deep reactive-ion etching (deep-RIE). As a result, a wide bandwidth of about 4 nm at −10 dB transmission-level was obtained with a tuning range of about 18 nm using the thermo-optic effect.