A Design of a Optical Fiber Network Fault Measurement Module Based on Coherent Detection

• Main Authors: Pei-Chi Chen, 陳佩琪
• Other Authors: Chen-Wen Tarn
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/525spr

碩士 === 國立臺灣科技大學 === 電子工程系 === 103 === We present a method to measure the fault location in the optical fiber network based on the approach of coherent detection. The fault location monitoring of an optical fiber system can be achieved by measuring the interference signal that is formed by the reference signal and the test signal. In the set up, the Fabry-Perot Laser Diode is used as the light source to carry a frequency-sweep sinusoidal signal into the fiber-optic network. The signal can then be sent through the optical coupler divide the probe signal into the test signal and the reference signal. Using optical circulator to sent the reflect signal into the second optical coupler, where the two signal meet and interfere. Through the electro-optic effect of the photodetector the interfered optical signal is received and converted into an electrical signal that is time varying. By analyzing the signal intensity over time and converting it into the length of the optical fiber, the location of breakpoint or fusion point in the optical fiber network can be determined. The method we present has the advantages of simple architecture and low manufacturing cost. The features make it easier to produce and set up in the optical fiber communication system.