Patent ID: 8837937

Claim:
A detecting device for detecting insertion loss of fiber route and return loss of individual events in an optical fiber network, comprising: a frequency modulated continuous signal generator for determining whether to generate a continuous cyclic frequency modulated (FM) signal according to a control signal; a laser emitter connected with the frequency modulated continuous signal generator for outputting common detecting light, or combining the common detecting light with the FM signal to produce FM detecting light; a directional coupler having a first connection port connected to the laser emitter to receive either the common detecting light or the FM detecting light; and a second connection port transmitting either the common detecting light or the FM detecting light to an optical fiber network, and receiving a return signal of the common detecting light or the FM detecting light; a photo detector connecting to a third connection port of the directional coupler for converting the return signal of the common detecting light or the FM detecting light into electrical signal and selectively connecting to a first path or a second path; a mixer on the first path and connecting with the photo detector for receiving the FM signal output by the frequency modulated continuous signal generator and the return signal of the FM detecting light output by the photo detector, and performing frequency mixing to generate a beat frequency signal; a first amplifier on the first path and connected with the mixer for amplifying the beat frequency signal; a second amplifier on the second path and connected with the photo detector for receiving the electrical signal converted from the return signal of the common detecting light and amplifying the electrical signal; an analog/digital converter (ADC) selectively connecting to the first amplifier or the second amplifier for converting the analog signal amplified by the first amplifier or the second amplifier into a digital signal; and a signal processing analysis unit connected with the ADC for receiving the digital signal; wherein the digital signal received from the first path is analyzed to obtain a position and return loss of any event on the optical fiber network; and the digital signal received from the second path is analyzed to obtain the insertion loss and total return loss of the optical fiber network.