| 摘要 |
PURPOSE:To permit the exchange of optical signals with fewer number of photo delay elements than time division multiplex by connecting a photo delay circuit consisting of delay elements which use one time slot as a delay time unit and that consisting of delay elements which use n number of time slots as a deley time unit using a photo switch. CONSTITUTION:A delay circuit 8 conncects n pieces of delay elements in series which delay an input photo signal for t (one time slot time), and installs a photo switch in input or output side of each delay element. The time-dividing multiplexed (N-plexed) photo signal of each time slot which is input to the delay circuit 8 from an input highway 4 passes through thenecessary number of stages in the delay elements 11, is output by a photo switch 3i, and is input to the delay circuit 9 via n x m photo switch 2. The delay circuit 9 connects m pieces of delay elements 21 in series which delay input photo signal for n times t, and installs a photo coupler in input or output side of each delay element. The photo signal input from the photo coupler 4 passes through the delay element 21 for j stages, and is output from an output highway 5; provided that (m-1)n<N<=mn. |
