Research Of The Distributed Optical Fiber Sensor Technology Based On The Optical Frequency Domain Reflectometer

The fiber sensor technology has been forming with the development of the optical communication. For the fiber sensor has many advantages which can't be found in ordinary sensors, such as powerful anti-electromagnetic interference, strong environment adaptability and broad detecting range, it has been paid great attention and has got great development in the past 30 years. The distributed optical fiber sensor can best express the advantage of the fiber. Besides the features of the ordinary fiber sensors, it can accurately measure the fiber's information of stress, temperature, vibration, and damage without forming a loop, therefore, the distributed fiber sensor has become the hotspot these years.The optical time domain reflectometer(OTDR) technology is probed by the narrow back pulses of optical radiation, the spatial resolution can be improved as the pulses are shortened and the measurement band-width is broadened. However, it results in the decrease of the pulse energy and increases of noise level and consequently in the decrease of dynamical range, so there is a trade-off between dynamical range and space resolution. To solve this problem, the optical frequency domain reflectometry(OFDR) is put forward.This paper summarizes the development situation of the fiber sensors and the comparison among different fiber sensors, points out the strategy and advantages of distributed fiber sensor, analyzes the key technologies of the OFDR by studying the principle of OFDR firstly, discusses the parameters of the apparatus which constitute the OFDR system, studies the distributed fiber sensor by theoretical and emulational methods, and gets a comparison to the OTDR.