Study On Characteristics Of Photonic Crystal Fibers And Its Applications

Photonic crystal fibers(PCFs)are a new kind of fibers with photonic crystalstructures. PCFs have many unique properties such as endless single mode operation,controllable dispersion, high birefringence etc, compared with traditional fibers.These properties have great advantages and value in nonlinear optics andoptoelectronics. PCFs and the devices based on PCFs have exhibited great applicationpotentials in all-optical communication, and have become a hot research topic inoptical communication.In this dissertation, four major tasks are fulfilled. Firstly, the program isindependently written using Matlab based on the semivectorial difference method.Secondly, taking advantage of the controllable dispersion, a novel PCF is proposed forbroadband dispersion compensation. The numerical results show that it cancompensate 23 times of the length of conventional single-mode fiber within±0.2ps/nm/km over 330nm wavelength range. This special fiber has significantapplication in WDM system and provides theoretical basis for exploiting noveldispersion conpensation fiber. Thirdly, the fundamental mode characteristics in thetapered PCF are analyzed. The influence of the cladding structural parameters ofTPCF on the mode indices, effective area, energe density and dispersion properties arestudied. The studies provide theoretical guidance for applications of dispersionconpensation and nonlinearity based on TPCE Finally, the propagations of ultrashortfemtosecond pulses in PCF are also studied. We discussed the effect of differentparameters on SC generation in PCFs, including effect of the initial input power, thepropagation distance, high order dispersion and nonlinearity. The mechanisms ofspectra evolution are analyzed.The dissertation consists of 6 chapters. The main research results aresummarized as follows:Chapter 1 is to briefly introduce the PCFs, including their developing background, their present researching states, manufacturing methods and prospectiveapplications.Chapter 2 presents the theory of the whole research. The characteristics of thePCF are analyzed with semivectorial finite difference method. The distribution of themode, the corresponding indices, normalized frequency and dispersion areinvestigated theoretically.Chapter 3 proposes a novel photonic crystal fiber for broadband dispersioncompensation. The numerical results show this DCPCF can compensate 23 times oflength of Coming SMF-28 within±0.2ps/nm/km over 330nm wavelength range.Chapter 4 studies the fundamental characteristics of tapered photonic crystalfiber based on semivectorial finite difference method.Chapter 5 focuses on the propagation of ultrashort femtosecond pulses inphotonic crystal fiber.Chapter 6 includes the conclusions and prospective views.