Combined fiber optic network for communication and measurement using a hetero-core spliced fiber optic sensor

摘要

We have developed a fiber optic network combining communication and measurement using a hetero-core spliced fiber optic sensor inserted into an existing communication line with a wavelength-division multiplexing (WDM) analogy. Switch modules using the proposed sensor were inserted into an actual communication line and the influence on the communication of the switch modules was examined. The communication link broke when approximately 21 dB is inflicted a loss on the communication light of 1.31-pm wavelength by the switch modules, the WDM filters and a fiberoptic coupler in the communication line. Because the amount of loss is the maximum allowable for a communication instrument, the proposed sensor has been clarified to have only the loss characteristic. If the loss is controlled to within tolerance for the communication wavelength, a measurement function can be added to a communication line by a comparatively simple method. It was also shown that a combined optical fiber network can be achieved, where the intensity of the communication light is measured. The combined method is highly cost effective, because it is not necessary to have a separate light source for measurement, WDM filters, and other elements in the communication line.