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Research On Transmission Characteristic Of Photonic Crystal Fiber And Applications In Optical Communications

Posted on:2016-03-25Degree:MasterType:Thesis
Country:ChinaCandidate:Y C HuangFull Text:PDF
GTID:2308330473959768Subject:Optics
Abstract/Summary:PDF Full Text Request
In recent years, as research continues and applications becomes wider constantly, the potential of photonic crystal fiber is getting more and more recognition. Especially much attention has been paid to its excellent transmission characteristics. Endless single-mode characteristics, flexible and controllable dispersion properties, high birefringence and high nonlinear characteristics make it have a wider application prospect in communication and sensors field. At the same time, study of its design is not just limited to strict periodic structure. Instead, researchers have tried a variety of new structures and introduced many other materials as dopants, hoping to get better properties and higher application value. This article will also put the transmission properties of photonic crystal fiber as the research target, and make full use of great freedom of design photonic crystal fiber. The main work is as follows:Guided by control variable method, a series of compared model was established. According to basic theory and analysis method on photonic crystal fiber, mainly the finite element method, simulation and analysis are progressed with the assistance of Comsol Multiphysics. Then the rules of transmission characteristics and the fiber structure were summarized. Transmission characteristics focused on are effective mode area, nonlinear effect and dispersion characteristics and as structure parameters varied consist of the hole diameter, lattice constant of photonic crystal, the number of air holes layer in the cladding and the number of missing air hole layers inside the cladding. These rules may work for the subsequent design of photonic crystal fiber, providing theoretical reference and basis.A new design of guiding-index photonic crystal fiber which possesses beam shaping effect and flexible control of dispersion has been proposed in this paper. It can shape Gaussian beam into circular hollow beam with certain dimension, which can be used in optical communication system with Cassegrain antenna to improve transmission efficiency by avoiding the loss of energy caused by the subreflector center reflection. In this paper, we established the model of the new fiber structure and analyzed it by simulation. What’s more, the geometry evaluation parameters of hollow beams was defined, calculated and analyzed. In addition, on the basis of the results of simulation, the transmission efficiency of Cassegrain antenna optical communication system were calculated, with or without the new photonic crystal fiber, on purpose of showing its effectiveness.A further optimization was made on the new fiber structure above. Its dispersion and confinement loss can be changed in a broad range by slightly adjusting structural parameters under condition that the hollow beam dimension remains about the same. Fairly practical properties, zero dispersion or flattened dispersion, can be obtained when structural parameters are set appropriately. A series of models with different parameters are analyzed and compared. Several modest design parameters are given as well.
Keywords/Search Tags:photonic crystal fiber(PCF), effective mode area, nonlinear effect, dispersion characteristics, hollow beam
PDF Full Text Request
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