Design And Implementation Of Fiber Insert-return Loss And Fault Detection System

This topic mainly develops an integrated, multifunctional fiberperformance testing system. The system can mainly test the optical insertion loss,return loss of main optical components and detection performance of opticalfiber links with their own output stability of light source, large dynamic range,high precision measurement of optical fiber performance metrics.The paperproposes effective optical test solutions and lock-in amplification detectiontechnology.Nowadays, foreign fiber optic communication test equipments arenot only the high price but also the complexity of the testing process, at the sametime, most of domestic fiber testers only have single testing function and areabsence of research for integration,multi-function performance fiber testingproduct, even some domestic scientific research institutions have developed thetest instrument of measuring optical insertion loss, optical return loss and faultlocation function.This topic is analyzed from the following aspects:(1)The paper has a in-depth analysis of test principle and realization methodfor optical return loss test, fault location, at the same time puts forward afeasibility scheme with high cost performance, optimization of optical returnloss test and fault location test after comparing and analyzing the advantages anddisadvantages of current adopted testing scheme.Finally, the topic compares andanalyzes the research and implementation method for weak photoelectric signallow noise processing technology to determine the feasibility scheme and systemarchitecture.(2)Analysis and design the hardware circuit of fiber optic detection systemin detail, while achieving test system hardware circuit structures by variousparameters.Based on the hardware circuit design, chip selection, power circuitestimation and design, lock-in amplifier to detect weak signals,design ahigh-performance, low-power, low-noise performance fiber optic detectionsystem.(3)By combining the various parameters of the test methods for softwareprogramming,designing application test function software and refining themodular design. In the integrated development environment MPLAB XIDEsoftware platform will write software code of stability of light source, optical insertion loss test, optical return loss test,fault location test and design moduleflow chart.(4)The system test and performance analysis of the overallparameters.Through standard optical power meter, optical device, the nominalfiber module testing a series of test equipment for various parameters.Themethod can verify the actual parameter test indexes, the expected design indexesand performance stability.The advantages of the fiber optic detection system are mainly in thefollowing aspects: First, dynamic range of the optical return loss, the minimumreflected optical power can detect-75dBm and the system can achieve1010class weak photocurrent detection; Second, high precision, light15min stableoutput stability0.018dB,1h stability0.02dB, fault location can distinguish theminimum distance2m; Third, low-cost, moderate cost and high-performancechip selection system. Ultimately it have good performance such as the opticalreturn loss, insertion loss of light, fault location detection multifunctional,integrated fiber optic tester.