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Study On The Influence Of Various Defects On The Characteristics Of Infrared Photonic Crystal Fiber

Posted on:2013-01-07Degree:MasterType:Thesis
Country:ChinaCandidate:Q Q HuFull Text:PDF
GTID:2218330371457594Subject:Optical Engineering
Abstract/Summary:PDF Full Text Request
With the rapid development of the national economy and the continuous progress of science and technology, the application fiber waveband is shifting from near-infrared band to the longer far-infrared band forward. Meanwhile, people are exploring more functions of the optical fiber, transmitting high-power energy through it and especially transmitting middle and far infrared laser, such as transmitting CO2 laser energy in surgical operation. In the past few decades, people have tested various kinds of fibers in different structures and different materials and perfected the transmission characteristic of the optical fiber. At present, Infrared optical fiber has become one of the hot topics in field of fiber.Since photonic crystal was proposed, its unique structure and characteristics become many scientists focus of research, which is different from that of traditional fiber such as high coupling efficiency, low bending loss, low non-linear, controllable dispersion, etc. Using optical fiber based on photonic crystal provides a new research idea for the development of infrared optical fiber with low loss and high transmitting power. Due to the complex structure of optical fiber based on photonic crystal, It is difficult to understand the micro-structure of quartz glass with periodic air holes in production of optical fiber.In this paper, firstly, we analyze the band gap, optical and loss characteristics of photonic crystal fiber deeply with PWM and FEM method. On this basis, the cross-section of the infrared photonic crystal fiber designed in this article is triangle structure. The lattice constant is 10.4μm, the air filling factor is 0.8, the radius of the fiber core is 20.8μm, and the layers are eight, which can transmit high power CO2 laser energy. Secondly, Considering the practicability of fiber, this paper focuses on the influence of the loss characteristics of PCF due to some defeats such as lack, dislocation, radius, deviation in shape of air column from limitations in the sample preparation process, building a variety of computing models and using COMSOL software which based on the FEM method. After emulation of a large number of sample models, the conclusions between structure parameters of defeat and characteristic parameters of infrared PCF are discussed. The results show that, defects can reduce loss of PCF within certain limits, but larger defects would seriously increase the loss of infrared PCF. For the actual preparation of the infrared PCF has an important vaule.
Keywords/Search Tags:Photonic Crystal Fiber, CO2 Laser, Plane Wave Method (PWM), Finite Element Method (FEM), Photonic Band Gap, Loss, Defect
PDF Full Text Request
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