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Research On The Characteristics Of Chromatic Dispersion And Nonlinearity In Photonic Crystal Fibers

Posted on:2008-01-02Degree:DoctorType:Dissertation
Country:ChinaCandidate:S G YangFull Text:PDF
GTID:1118360272477738Subject:Electronic Science and Technology
Abstract/Summary:PDF Full Text Request
Photonic crystal fiber (PCF) can have very large refractive index modulation and very flexible index profile. It just meets the requirement on large index modulation in dispersion-compensating fiber(DCF) and high nonlinear fiber. PCF-based DCFs and high nonlinear fibers have outstanding performance in chromatic dispersion and nonlinearity respectively, which have attracted much attention.To simulate PCF, the dissertation studies two modeling methods which are Finite Difference Time Domain (FDTD) method and Finite Difference Frequency Domain (FDFD) method. Based on the two methods, a PCF simulating software is developed. The software is very friendly in the interface, very easy to use and can simulate all kinds of PCF profile.Several theoretical designs and simulations have been carried out by using the software. First, a band-gap guiding PCF is investigated by FDTD and the frequency of the guiding mode, the leaky loss and the mode field profile of the fiber are obtained. Secondly a broad band dispersion-compensating PCF is proposed. By introducing a ring of large grapefruit holes in the inner cladding, the dispersion performance of the dual core PCF can be improved greatly. The chromatic dispersion of the fiber demonstrates linear evolution with wavelength in a bandwidth of more than 60 nm. Thirdly, a tunable dispersion-compensating PCF is proposed. When a specific ring of air holes in a single mode PCF is filled with index tunable polymer, the propagation mechanism of the PCF is changed and the chromatic dispersion of the PCF is changed to be high negative. Moreover the chromatic dispersion of the PCF can be tunable when the refractive index of the filled polymer is changed.The dissertation presents a whole research process concerning a PCF with large mode area and high negative dispersion on the theoretical design, experimentally fiber-drawing fabrication and the measurements of the chromatic dispersion and the mode field of the fiber. At first, a PCF with large mode field area and high negative dispersion is designed theoretically based on the condition of the practical fiber drawing. And then the PCF is drawn experimentally. The measurement results on the fabricated PCF demonstrate that the fiber has large mode field area and high negative dispersion simultaneously. To study the mode field of the fabricated PCF, a fiber mode field measurement system with high resolution and large dynamic range is developed. The mode field of the fabricated PCF is tested and the evolution of the mode field with wavelength is investigated.A slow light experiment based on Stimulated Brillouin Scattering (SBS) in a homemade high nonlinear PCF is demonstrated. Low loss splicing between the high nonlinear PCF and a single mode fiber is realized. The Brillouin gain characteristic of the high nonlinear PCF is tested and a slow light experiment is carried out based on the PCF. Up to 1/2 pulse width delay is achieved in only 50-m PCF. It also demonstrates that the delay time grows exponentially with the Brillouin gain.
Keywords/Search Tags:photonic crystal fiber, chromatic dispersion, nonlinear, Brillouin
PDF Full Text Request
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