| 摘要 |
PURPOSE:To attain two-way communication through one optical fiber cable and to constitute short-range optical communication inexpensively by using a light emitting element in common use for a light emitting element and a photodetector and connecting an optical fiber cable and a transmitter/receiver without using any optical connector. CONSTITUTION:A transmitter consists of a control circuit 1 for transmission/ reception signal, a frequency modulation/demodulation circuit 7 for signal and a light emitting element, e.g., a light emitting diode 8 in common use of a photodetector. A current flows in forward direction to the P-N junction of semiconductor in the diode 8, positive holes and electrons are injected to the N and P regions excessively, the excessive carriers are recombined, and a part of the energy is emitted as light. When the light having the energy being that of the forbidden band touches the P-N junction, the positive hole/electron pairs are formed to be an optical current and the P-N junction has electrooptic/ optoelectric converting characteristic in this way. The two-way communication is attained by utilizing one plastic optical fiber cable through the use of the characteristic. |
