Abstract

In order to increase the capacity of optical transmission systems, it is advantageous to use the high-parallel capability of optical wavelength division multiplexing (WDM) [1] techniques. Key devices for WDM-communication systems are optical demultiplexer. A variety of different devices, such as Mach-Zehnder filters [2], diffractive optical elements (DOE) [3], acousto-optical filters [4], transversal filters [5] and arrayed-waveguide gratings (AWG) [6,7] have been already developed. However, to realize a device with a higher functionality it is usefull to integrate waveguide devices with DOEs. As a special case of WDM functionality upgrade, we have considered a 1.55-μm WDM extension of an existing passive optical net (PON). In this paper we report, for the first time to our knowledge, of the fabrication of a fully integrated multichannel WDM-PON demultiplexer. The device is used to distribute 1.3-μm wavelength signals (1/N power) and to multiplex an 8-channel WDM spectrum at 1.55-μm wavelength with 200 Ghz channel spacing. Planar lightwave circuits (PLC), based on silica waveguides, are very attractive devices for these applications [8]. They allow high reliable and low cost production, due to their suitability for integration of optical components. Furthermore, the silica waveguides show low optical losses.

© 1998 Optical Society of America