OPTICAL FIBER TRANSMISSION SYSTEM

摘要

PURPOSE:To attain an optical fiber transmission system utilizing the inductive Raman diffusion effect of high efficiency, by repeating repetitively the exciting light source according to the modulation input synchronous with the output light of a signal light source for extremely short optical pulses of high levels. CONSTITUTION:The output lights of a signal light source 1 and an exciting light source 2 are synthesized by a multiplexing circuit 3 and made incident on an optical fiber 4. The output light wavelength of the light source 1 is shifted from that of a light source 2 by a characteristic amount owing to a medium of an optical fiber 4 and amplified inside the fiber 4 by the inductive Raman diffusion effect. The light source 1 is modulated by a binary code produced from the output signal of a gate circuit 8 that is controlled by the input information signal sent from a terminal 9. While the light source 2 produces an extremely short optical signal of a high level according to the output of a signal generating circuit 7 which produces the repeating signal synchronously with the clock signal of an input information signal supplied from a terminal 10. The output light waveform of the light source 2 is eliminated by a filter at the other end of the fiber 4 and made incident on a photodetector 6. Then the light wavelength is converted into electrical signals and delivered.