The Large Mode Area Photonic Crystal Fiber Research

With the thorough development of the information technology, all kinds of new communicating network technique continuously rushed out. However, because of excellent advantage of optical fibre communciation technology, especially, high speed and super capacity system was the best measure of various networks. With the communication statistics, the whole world'information which was transited by fibre network accounted for 80% in nowdays. So fibre communication technology had been to the important manner of communicating. Currently, fibre transmission technology is going along with the directin which is high speed, super capacity, long distance. Reportedly, the most transmisson capacity had reached more than 10Tb/s (42.7Gb/s×256). With the great demand of information transmission and fiber communication development, the new fibre technique, the new wdm, the new fibre amplifier and the new fibre laser had quickly advanced in the development of all sorts network, the transmission medium—optical fibre, also changed quickly.fibre techque had developed from conventional fibre to the new type which had sorts of structure and performance could meet demanding of different network envinorment. Photonic crystal fibre, which is the one of new pattern fibre, had been regard promisingly by academics and industry group. It was developed fast recent years, and had been to the most hotspot and most frontland of fibre technique field. Photonic crystal fibre had turned a new leaf for communication. Foreseeing, in the future, photonic crystal fibre would take place of the coventional fibre and would be the next generation of communicating fibre.The mostly researching of this dissertation was the mode area of photonic crystal fibre and how to realize the large mode area. On the basis of introducing the novel attributes of this fibre, the capability principles—electronmagnetism texture was analyzed. Among the kinds of numerical simulating method, multipole method and effective index method was applied to analyze different structure fibre, simulate the electronmagnetic field, conclude the structure parameters which influenced the mode area.At last, analyzing the relationship of confinement loss, numerical aperture, nonlinear coefficient and single mode character with the mode area. Integratly considering sorts of factor, the articles introduced one practical passive LMA single mode PCF and this PCF had little confinement loss. Photonic band gap fibre was also one of important PCFs and it is potential to be applied in sorts of optoelectronic device. Especially, Er doped fibre which was succeeded perfoming in fibre amplifier and fiber laser. PBG-PCF is different from TIR-PCF. This articles simulated the electronmagnetic field of PBG-PCF and computed the relation of the structure parameters with mode area and confinement loss. The fabrication craft is more difficult than other fibres, so the large application of PBG-PCF is blocked all the time.At last, this article concluded how to test the mode area of LMA-TIR-PCF which was fabricated by the 23th academic of CECT in SHANGHAI. Because of the sparsity of mode area testing method, it introduced one new convenient method and testing precision was high.