Software Design And Development Of Hybrid Signal Optical Time Domain Reflectometer

With the rapid development of the communications industry in the 21 st century,optical fiber communication has become the mainstream technology of the communications industry.A substantial increase in the use of fiber,will inevitably lead to a large number of fiber failure.How to quickly and accurately locate the point of failure has become the key to solve the problem of fiber failure.In the fiber fault location system,OTDR is the most widely used,most frequently used detection equipment.OTDR can non-destructive detection of fiber,fiber attenuation information and the location of the fault point.The traditional pulse OTDR has the spatial contradiction that the spatial resolution and the dynamic range can not be improved at the same time.Although the chaotic OTDR can obtain the constant spatial resolution in the measurable range,the attenuation of fiber can not be obtained because of the continuous chaotic light information.To solve this problem,a chaotic-pulse hybrid signal optical time-domain reflectometer is developed.The working principle is to measure the Fresnel reflection and backward Rayleigh scattering in the fiber by continuous chaotic light and discrete pulsed light respectively,and successfully developed a prototype.By using G.652.B single mode fiber as the test fiber,the parameter specifications of the prototype are tested and analyzed.Measured results show that the prototype can realize a range-independent resolution of 35 cm within at least 104 km.The prototype also can reach 50 km on fiber loss events.As the LabVIEW development platform in the data acquisition,processing and control has a unique advantage,as well as visual programming,portability,easy to use,etc.,it is the virtual instrument development platform for the best choice.And the combination of computer,OTDR has a friendly interface,a strong data processing capabilities and a good development environment,so this article using the LabVIEW development platform to complete the mixed-signal optical time domain reflectometer detection software development,the main study content is as follows:1?We have studied the common types of faults in optical fiber faults,investigated the commonly used detection equipment and compared the existing optical time domain reflection methods.Combining the pulse method and the chaos method,we have proposed a chaotic-pulse hybrid signal optical time-domain reflectometer system.The principle is to measure the Fresnel reflection and backward Rayleigh scattering in the fiber by continuous chaotic light and discrete pulsed light respectively.2?Compared with the characteristics of the system and the selection of the data acquisition card in the system,and LabVIEW development platform has the advantages of data acquisition,processing and control,we selects the LabVIEW development platform to complete chaotic-pulse hybrid signal optical time-domain reflectometer supporting detection software development.3?A prototype of chaotic-pulse hybrid signal optical time-domain reflectometer was successfully developed,the prototype of the spatial resolution and measurement range indicators were analyzed and verified.4?By using G.652.B single mode fiber as the test fiber,the parameter specifications of the prototype are tested and analyzed.Measured results show that the prototype can realize a range-independent resolution of 35 cm within at least 104 km.The prototype also can reach 50 km on fiber loss events.