| 摘要 |
<p>A method of extracting a data bit stream from an optical signal in a differential polarisation shift keying format and transmitted along an optical fibre (21), comprises the steps of: directing the optical signal emerging from the fibre (21) onto a detector assembly (23) having an array of at least six individual detectors (24) each having associated therewith a polarisation filter (Figure 4), the detectors being paired with the two detectors of each pair having mutually orthogonal polarisation filters and the three pairs of filters forming a set of mutually orthogonal axes in the Poincaré sphere representation; sampling the outputs from the detectors (24) at substantially the same bit rate as that of the transmitted data stream; and analysing the sampled outputs of the three pairs of detectors to derive the transmitted data stream. Also disclosed are a receiver (Figure 2) for extracting a data bit stream by the method aforesaid and also a method of generating an optical signal in a differential polarisation shift keying format.</p> |
