| 摘要 |
PURPOSE:To decrease the loss arising from the insertion of an optical sensor into a communication line and to simplify the system by inserting the optical sensor between one end on one side of a multiplexer/demultiplexer by which an arbitrary one among different wavelengths is extracted and one end on the other side thereof. CONSTITUTION:The multiplexer/demultiplexer 8 is provided in the communica tion line in which light signals of the different wavelengths are transmitted by a wavelength multiplexing method is provided and the optical fiber type sensor 6 is interposed between terminals (b) and (d) of the mliplexer/ demultiplexer 8. Only the light signal of the wavelength lambda2, therefore, passes the optical fiber type sensor 6. Since the light signal of the wavelength lambda1 passes only the multiplexer/demultiplexer 8, the attenuation quantity thereof decreases and the loss arising from the insertion of the optical sensor 6 is decreased. In addition, the cost is reduced. |
