Study On The Transmission Properties And Structure Design Of Bragg Fiber

Bragg fiber, which can be also called Omniguide fiber, was firstly presented by Yariv in 1978. Bragg fiber is one of 1-D photonic crystal fibers, of which the cladding is a one-dimensional photonic crystal constructed by alternating layers of dielectric media with high and low refractive indices. Since the end of the 20th entury, many excited achievements of the photonic crystals and the photonic crystal fibers have been demonstrated, the Bragg fibers have obtained more and more attentions, and many colleges and institutes around the world have spent a great deal of endeavour on the theories and applications researches of Bragg fibers. Both theories and experiments show that Bragg fibres have many novel properties, such as large mode area, tailorable dispersion, polarization independent transmission, extremely low non-linearity, and so on. It will be a bright application foreground on the special fibers, photonic devices, fiber sensor and high-power transmission.Because of the fabrication of the Bragg fiber is still very difficult, there have few literatures about the Bragg fiber by far. In this dissertation, the transmission properties of the Bragg fibers are analyzed and a novel Bragg fiber is designed for a special case.The main contents are as follows.1. The photonic band gaps of common Bragg fibers have been analyzed by using the plane wave expansion method (PWM). By the model of the effective-medium structure, the two-dimensional lattice structure of circular PCF can be approximated to a one-dimensional structure, and the photonic band gaps can be calculated by the 1-D PWM.Considering the analogy between Bragg fiber and circular PCF, the band diagram of Bragg fibers can be obtained with the one-dimensional approximation.2. The modes of the Bragg fibers are demonstrated in detail including the transmission properties of the power loss, the chromatic dispersion and the non-linearity coefficient.3. The characteristics of the material for fabrcating Bragg fibers have been reviewed. In this paper, we have presented two implementations of the silica-air Bragg fiber with its band structure and potential applications. The preparation techniques for air-silica Bragg fibers have been investigated.