Method and apparatus for reception of optical signals

Abstract

An apparatus and method are provided for receiving an optical signal having an optical carrier component and at least one information-bearing optical sideband. In general, an optical filter arrangement () is used to separate the optical carrier component from the information-bearing optical sideband. First and second optical splitters () divide the optical power in the optical carrier and the optical sideband, respectively, into corresponding sub-components. The sub-components of the optical carrier have substantially orthogonal polarisation states, which is an optional characteristic of the sideband sub-components. First and second optical coupling devices () respectively each combine one of the optical carrier sub-components with a corresponding one of the optical sideband sub-components. Optical detectors () detect the outputs of the combiners (). The arrangement is able to achieve a number of the benefits of coherent optical heterodyne receivers, particularly when used in combination with advanced coding and modulation methods, while avoiding the need, and associated complexity, of providing an optical oscillator at the receiver.