Developments in and applications of fiber perimeter detection sensors

For many yesrs optical fiber was the answer looking far the question.Now,after years of optical-fiber product and digital-signal process(DSP) techniques'continued development,a range of fiber optic sensors are used in perimeter intrusion detection.The optical fiber sensors used in intrusion detection are based on many different principles,such as Optical Time-domain Reflectometry(OTDR)technique,interferometer technique.There are two stages in fiber perimeter detection sensors'development.The sensors of first stage can just judge the styles of intrusion.However,the sensors of second stage can also tell thepo- sition of intrusion.For each fiber perimeter detection sensors,they have different characteristics and their realization difficulties are variable.This paper introduces and analyzes the fiber semor technohgy which could apply on perimeter detection now.The advantage and disadvantage of each scheme are also discussed.And many products based on the discussed principle,which are available on marker,are also mentioned.