| 摘要 |
PROBLEM TO BE SOLVED: To dispense with conrolling of light level, in inserting a high-speed optical interface in a light multiplex branching and inserting device. SOLUTION: An optical coupler 2-6, which is free of the dependence on wavelength in a main signal wavelength band, is used for the wave combination part of a passage channel and an insertion channel. A device 2-3 for fixing the level of the passage channel and devices 2-12 and 2-22 for fixing the level of the insertion channel are provided. Even when the light level of the insertion channel is not sufficient, as compared with the passage channel, a channel unit optical amplifiers 4-12 and 4-22 are installed at the output part of the optical interface part of the insertion channel, so as to secure necessary SNR(signal-to-noise ratio). This device restrains it from deteriorating optical SNR, being accumulated in the band of other channel, by adding band-pass filters 4-13 and 4-14 to the output part of that channel unit light amplifier. That band-pass filter can be mounted and removed or change its wavelength with respect to arbitrary optional wavelength. |
