InP-based compact reflection-type transversal filter

Abstract

We developed a reflection-type 4x1 transversal filter (TF) on an InP substrate as a compact and low-loss wavelength multiplexer (MUX) for monolithically integrated light source arrays. The filter has a satisfactory MUX function and is very compact of about 900 Pm x 50 Pm which is one twentieth of a size of a conventional 4x1 TF. It is suitable for a MUX of a monolithically integrated light source array thanks to its compactness and input/output-port arrangement.