Light pipe array as coupling adaptor between fiber array and free-space wavelength division demultiplexer

Abstract

A light pipe array (LPA) is proposed as a coupling adaptor between a commercial fiber array and a free-space dense wavelength division demultiplexer (free-space DWDDM). The LPA has been fabricated on a silicon-on-insulator wafer using the semiconductor fabrication technology and coated with a thermal oxidation layer on its input and Output surfaces as an antireflection film. In the experiment, the free-space DWDDM system with the LPA has been demonstrated with an insertion loss of 2.4 dB and an adjacent cross-talk of - 17 dB.