| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a detector capable of suppressing reduction of resolution of a signal even when phase difference between adjacent phases is reduced by multi-phase modulation in the detector for detecting an optical modulation wave of linearly polarized light whose phase is modulated according to digital data. <P>SOLUTION: The detector has a beam splitter 11 branching the optical modulation wave of linearly polarized light into paths 15 and 16, a one bit delayer 12 for delaying the phase of the optical modulation wave on the path 16 by one bit of the digital data, a phase difference plate 13 for rotating the polarization axis of the optical modulation wave on the path 16 by 90°, an optical coupler 14 for superposing optical modulation waves via the paths 15 and 16 and converting the waves into a superposition wave having a polarization state changing according to phase difference between phases of the optical modulation waves and a polarization detecting part 3 for receiving the superposition wave and converting the polarization state into an electric signal. <P>COPYRIGHT: (C)2008,JPO&INPIT |
