2 × 2 16-ch silicon photonics wavelength-selective switch based on waveguide gratings.

We demonstrate a 2 x 2 16-ch silicon photonics wavelength-selective switch consisting of contra-directional couplers and thermo-optic Mach-Zehnder switches. The contra-directional couplers are based on sidewall corrugated Bragg gratings with an unlimited free spectral range and thus enable the device to operate over a very wide wavelength range of the C- and L-band. We obtain a fiber-to-fiber insertion loss of 9.2 dB, an on-chip loss of 5.4 dB, a 3-dB bandwidth of 4.2 nm, a bar-port extinction of 15.0 dB, and a cross-port extinction of 23.0 dB, all in 16-ch average. An average trimming power for the bar states and an average switching power for the cross states are 3.8 mW (sigma = 2.3 mW) and 15.6 mW (sigma = 2.1 mW), respectively. The wavelength dependence of the spectral responses and the resonant effect from the apodization are discussed in detail to show how to further improve the spectral performance. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement