Research On The Wave Length Response Of Intelmodal Interference In PMF

In optical fiber sensing field, Polarization-Maintaining Fiber(PMF) is widespreadedused because of polarization property, high signal to noise ratio and large amount ofinformation in coherent communication. Intermodal interference in PMF is realized byenergy interchange between several modes in single fiber.This interference technologyhas a better environment interference characteristics and is more stable than thetraditional interference technology.As the statement above,PMF has a special use in thefield of optical fiber sensing.The objectives of this paper is about the wavelength response of intermodalinterference in Polarization-Maintaining Fibers.This paper introduces the theory ofMach-Zehnder interferometric sensor which is based on fiber model theory of ideal stepindex fiber of electromagnetic field model.The typical applications of optical fiber M-Zinterferometric sensor brings out intermodel interference theory of PMF. This paperfocuses on panda fiber and dual-mode photonic crystal fiber and analysis the wavelengthresponse of Intermodal interference in Polarization-Maintaining Fibers. The theory isproved by the experiment.The main contents are as follows:Firstly, the optical transmission mode theory of deal step index fiber is studied basedon electromagnetic theory. By discussing the different mode’s interferometric theory ofdeal step index fiber, the Simulation phenomena of intermodal interference between LP01and LP11is got.Secondly, the condition of interference between LP01and LP11of the panda fiber andtwo-mode photonic crystal fiber is numerical simulated by finite element method. Themode field of panda fiber and photonic crystal fiber are simulated and contrasted inthe conditions of satisfying the intermodal interference’s cut-off wavelength.Thirdly, the wavelength response features of Intermodal interference of panda fiberand two-mode photonic crystal fiber are simulated and calculated. The main reaseachparameters have intermodal interference transmission constant difference, intermodal interference beat length, and the output intensity when the intermodal interference phasedifference in transmission constant.At last, an experiment is set up to observation and analysis the phenomena ofintermodal interference in panda fiber and dual-mode photonic crystal fiber, verify thediscipline of wavelength change with the beat length, Analysis experimentally thediscipline of the output intensity with the output wavelength in some the phase differencebetween model.