| 摘要 |
PURPOSE:To prevent a signal from being reproduced at a receiving side other than an object receiving side by multiplexing a noninverting optical output and an inverted optical output outputted from plural laser diodes with different wavelength at a multiplexer, sending the synthesized signal to an optical fiber, demultiplexing the received optical output at the receiving side with a demultiplexer for each wavelength and reproducing the signal into an original signal. CONSTITUTION:A noninverting output is outputted from one of two laser diodes 3, 4 generating an optical output with a different wavelength and an inverted output is outputted from the other, the outputs are multiplexed by a multiplexer 5 and sent to an optical fiber 6, the receiving side demultiplexes the received optical output for each wavelength and photodiodes 8, 9 reproduce the output into the original signal. Thus, the intensity of the optical output sent in the optical fiber 6 is almost unchanged. Even when the signal is leaked from the optical fiber 6 during the transmission, the receiving side not having a demultiplexer demultiplexing the incoming optical output for each wavelength cannot reproduce the signal. |
