| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a delay demodulation device capable of reducing an amount of polarization separation and to provide a method of adjusting the phase of the delay demodulation device. <P>SOLUTION: The delay demodulation device 1 includes: first and second Mach-Zehnder interferometers 4, 5 each of which includes two arm waveguides having different lengths and in each of which a DQPSK signal is branched and to which the branched signal is input; a 1/2 wavelength plate 47 arranged on the two arm waveguides of respective Mach-Zehnder interferometers 4, 5; first heaters A, B and second heaters C, D which are formed on the two arm waveguides 8, 9 of the first Mach-Zehnder interferometer 4 with the 1/2 waveguide plate 47 interposed in-between; and first heaters E, F and second heaters G, H which are formed on the two arm waveguides 12, 13 of the second Match-Zehnder interferometer 5 with the 1/2 wavelength plate 47 interposed in-between. The first heaters and the second heaters are separately driven as polarization separation amount adjusting heaters and phase trimming heaters. <P>COPYRIGHT: (C)2010,JPO&INPIT |
