Photonic Crystal Fiber Mode Field Distribution And Dispersion Characteristics Of The Study

Since the 90's, the basic reseach and application of photonic crystal and photonic crystal fibers(PCF) have received a growing attention in the field of optoelectronics. As a new kind of optical fiber, the PCF has many unique optical characteristics and is a new direction of the optical fiber technology's development. So the researches in this dissertation have great scientific and application significance.The theoretical study in the mode field distribution and dispersion feature of photonic crystals fibers is discussed in this paper. The summary of the dissertation is as follows:(1) The basic conception of the photonic crystal and photonic crystal fibers are introduced, and PCF'dispersion properties ,application and present development are discussed.(2) The effective index model and localized orthogonal fuction model of photonic crystal fibers are analyzed detaily in theory. The plane wave expansion metod is introduced briefly.(3) Based on a scalar approximation, the mode field distribution feature, the effective index, and the normalization costant in triangular lattice photonic crystal fibers are simulated numerically with the effective index method. We find that the PCF can be designed to support only the fundamental guided mode at every wavelength. Then we present the dispersion and nearly zero ultraflattened dispersion of PCF and those variation relationship with the wavelength and the structure of PCF, which is significant for the design of PCF.(4) Based on a scalar approximation, the properties in square-structured photonic crystal fibers are simulated numerically with localized orthogonal function method. The transverse electromagnetic field was expanded by cosine functions, so the propagation constant could be calculated by recasting the Maxwell equation into eigen equation, and then we studied the propagation properties of the modes in square lattice PCF.This dissertation can supply a theoretical support for designing a photonic crystal fibers with certain waveguide modes and dispersion properties.