Phase error compensation for multilayered AWG in LCOS-based WSS

Abstract

We propose a novel method to compensate for the phase errors of a multilayered arrayed waveguide grating (AWG) used in a liquid-crystal-on-silicon (LCOS)-based wavelength selective switch (WSS). In this scheme, an additional LCOS is employed to externally compensate for the phase errors of the AWG in a layer-by-layer manner for both planes of polarization. This compensation scheme enables us to improve the yield of the WSS: specifically, we demonstrate that the additional LCOS drastically reduces the loss and polarization-dependent loss (PDL) of the WSS.