| 摘要 |
PURPOSE: To make frequencies of all transmitters stable by providing an optical heterodyne device to each of a plurality of optical transmitters placed spatially adjacent to each other. CONSTITUTION: A transmitting equipment group 10 is made up of a plurality of transmitters 1-n, placed spatially adjacent to each other, and the group 10 has a common coherent optical heterodyne device 2. The device 2 applies heterodyne processing between optical information signals S1 -Sn , whose channel carrier frequencies are f1 -fn emitted from the transmitters 1-n and frequencies on reference frequency lines L1 -Ln from a comb-line generator 4 to allow a filter 30 to provide an output of a filter signal FS. Based on the signal FS, a controller 34 cancels a frequency change fa in the frequencies f1 -fn of the transmitters 1-n. Thus, the frequency interval of the transmitters is made stable, and a possibility danger of crosstalk for a large number of the transmitters is avoided without making the configuration complicated. |
