Silicon Photonics Wavelength Selective Switch with Unlimited Free Spectral Range

We propose a novel silicon photonics wavelength selective switch (WSS) with sidewall-corrugated contra-directional couplers (C-DCs), which has an unlimited free spectral range and is suitable for broadband operation. Fabricated 2 × 2 1-ch and 2-ch WSSs demonstrate the expected operation with channel wavelengths of 1532 and 1553 nm, a 3-dB bandwidth of ∼3 nm, a flattop spectral shape, and an outban...