An Optically Preamplified 1 Gbit/s/channel Multichannel Grating Demultiplexer Receiver

Abstract

The Multichannel Grating Demultiplexer (MGD)1 receiver is an attractive component for High Density Wavelength Division Multiplexing (HDWDM) systems. It combines a diffraction grating with an array receiver to provide multiple channel access. However, demultiplexer losses and the need for array operation may lead to insufficient receiver sensitivity for some applications. To improve sensitivity a semiconductor laser amplifier (SCLA) has been included before the MGD. The wide gain spectrum allows a single SCLA to preamplify many parallel HDWDM channels2, while peak optical input, and consequently intensity modulation (IM) crosstalk, is minimised3. The MGD also provides a ~2.6 nm optical filter for the spontaneous emission, reducing its noise contribution at the receiver.