FIBER OPTIC TWO MODE INTERFEROMETRIC SENSORS FOR THE DETECTION OF ABNORMAL STATUS AND THE SIGNAL PROCESSING METHOD

A fiber optic two mode interferometric sensor for detecting an abnormal status and a signal processing method using the same are provided to detect the abnormal status using an optical fiber sensor and an optical fiber sensor system. A fiber optic two mode interferometric sensor for detecting an abnormal status includes a melted connection part, and a signal processor. The melted connection part is aligned to a center of two cores of the optical fibers. The signal processor performs a signal processing operation. Light entered the waveguide from a laser diode enters a detection optical fiber. The signal processor obtains data from a sensor for certain time intervals. The data obtained for certain time intervals are analyzed to set an alarm level and a hazard level. Then, whether the absolute level is smaller than a reference level set by a sure is determined. When the absolute level is smaller than the reference level, it is determined that the optical fiber is cut.