Photonic frequency division multiplexed FIFO buffer

A photonic frequency division multiplexed FIFO buffer for inputting a plurality of input optical signals on a time division multiplexed input highway and outputting output optical signals at timeslots on a time division multiplexed output highway, comprising:

• splitter means for splitting the input optical signals into two;
• frequency convertor means, connected with one output of the splitter means, for converting the input optical signals into sequentially different frequency channels;
• a plurality of loop shaped optical waveguide delay lines for storing the input optical signals;
• a plurality of 2.times.2 optical switch means for connecting the loop shaped optical waveguide delay lines in series with an output of the frequency convertor means, and selectively transferring the input optical signals among the loop shaped optical waveguide delay lines;
• 1.times.2 frequency channel selector means, connected at a last stage of the loop shaped optical waveguide delay lines, for selectively outputting optical signals in specific frequency channels among the input optical signals stored by the last stage of the loop shaped optical waveguide delay lines as the output optical signals to the output highway;
• signal output control means for controlling an output timing of the output optical signals from the 1.times.2 frequency channel selector means;
• and
• buffer control means for generating a control signal for controlling a selective transferring by each of the 2.times.2 optical switch means and a selective outputting by the 1.times.2 frequency channel selector means according to another output of the splitter means and the output timing controlled by the signal output control means.