Guided-wave multi/demultiplexers with high stopband rejection

Abstract

A new guided-wave multi/demultiplexer with high stopband rejection is made using high-silica embedded channel waveguides. This consists of three directional couplers of the same structure, that is, the second and third directional couplers are connected with two output waveguides from the first directional coupler, which suppresses undesired optical signals. This optical device is fabricated using low temperature CVD, lithography, and a reactive ion etching process. It is possible to apply a high-reliability fail-safe module, two-way repeater transmission module using wavelength division multiplexing; it also has other uses.