| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for improving reception of optical PSK signals transmitted in systems employing narrowband optical filtering. <P>SOLUTION: The optical PSK signals are converted at a receiver into two intensity-modulated signals and a desired amplitude imbalance is introduced between the two signals. An optical receiving apparatus 100 comprises an interferometer 110 for receiving the PSK signals. The interferometer 110 is preferably a Mach-Zehnder delay interferometer (MZDI) that provides a delay of about one bit between the arms 111A, 111B of the interferometer 110. The interferometer 110 converts incoming PSK signals into a first and second optical intensity-modulated signals (e.g., each signal at the constructive and destructive output ports of the MZDI signals). The first and second optical intensity-modulated signals are output from the interferometer 110 on output ports 110A and 110B, respectively. Two photodiodes 115A, 115B are respectively coupled to the output ports 110A, 110B of the interferometer 110. The photodiodes 115A, 115B are used to differentially detect the first and second optical intensity-modulated signals and generate electrical intensity-modulated signal (i.e., generate photocurrents representative of the first and second optical intensity-modulated signals). The photodiodes 115A, 115B are preferably identical InP waveguide pin photodiodes. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
