| 摘要 |
<P>PROBLEM TO BE SOLVED: To attain detection of the temporal changes in a wavelength error signal in an optical multiplex communication, to enable the wavelength error signal to be identified for each user in a time division multiplexing signal, and to attain simplification of a user-side device and reduction of costs. <P>SOLUTION: A wavelength error signal detector includes: a light beam splitter (BS); a first photodetector for receiving one output of the BS; an amplifier connected to the first photodetector; an optical filter for giving a wavelength reference to another output of the BS; a second photodetector for receiving the output of the optical filter; a subtractor for subtracting the output of the amplifier from the output of the second photodetector; and an AD converter connected to the subtractor. When the optical signal of a desired wavelength is inputted, the gain of the amplifier is adjusted so that the output of the subtractor becomes 0. Thus, a wavelength error signal from the desired wavelength of the input optical signal can be obtained, from the output of the subtractor. According to a sampling trigger signal given to the AD converter, the output of the subtractor can be monitored at arbitrary time intervals, so that a temporal change in the wavelength error signal can be observed. <P>COPYRIGHT: (C)2010,JPO&INPIT |
