Photonics Research, 2017, 5 (4): 04000340, Published Online: Oct. 10, 2018
Design of low-energy on-chip electro-optical 1 × M wavelength-selective switches
Abstract
A theoretical design is presented for a 1 × M wavelength-selective switch (WSS) that routes any one of N incoming wavelength signals to any one of M output ports. This planar on-chip device comprises a 1 × N demultiplexer, a group of N switching “trees” actuated by electro-optical or thermo-optical means, and an M -fold set of N × 1 multiplexers. Trees utilize 1 × 2 switches. The WSS insertion loss is proportional to [log 2 ( M + N + 1 ) ]. Along with cross talk from trees, cross talk is present at each cross-illuminated waveguide intersection within the WSS, and there are at most N 1 such crossings per path. These loss and cross talk properties will likely place a practical limit of N = M = 16 upon the WSS size. By constraining the 1 × 2 switching energy to ~ 1 fJ / bit , we find that resonant, narrowband 1 × 2 switches are required. The 1 × 2
Richard Soref. Design of low-energy on-chip electro-optical 1 ×