The Research On Characteristic Of Electronic Controlled Splitter Based On Photonic Crystal

As the 3G network is more and more widely used, the demand of high-speed accessnetwork is increasing rapidly. The most effective and direct method to increase the bandwidthof access network is fiber-optic access, what is FTTH. And the splitter is one of the extremelyimportant function devices in FTTH system. As a new type of material, due to its highefficient light guide function and lossless transmission, .photonic crystal is widely used tomake into devices such as beam splitter, WDM and demultiplexer and so on .In this thesis, the conduction mechanism of light wave in photonic crystal is introducedfirstly. Based on that theory, a new Y-type of 1×4 controlled photonic crystal splitter, which ismade up of three cascade 60°angle in two-dimensional photonic crystal, is proposed. Withthe help of the plane wave method and finite difference time domain method, the transmissioncharacteristics of optical signals in photonic crystal splitter is investigated when the radius ofdielectric cylinder at the branch is different.Therefore, photonic crystal beam splitter withimproved structures is designed and analyzed. Based on that, photonic crystal beam splitterwith uniformed and non-uniformed distributed are designed respectively. Secondly, theprinciple of photonic crystal optical switches is studied On the basis of that structure, fourswitches are generated through the introduction of point defects, and tunable photonic crystalresonator is generated when the point defects are filled with Phenylacetylene liquid crystalmaterial. By analyzing the impact of point defects on the beam splitter performance ,the bestpoint-defect parameters have been identified. According to the theory of defect modemigration, ten kinds of"on-and-off"control combinations of both uniformly distributed andnon-uniformly distributed photonic crystal beam splitter are achieved, such as 1111,0111,1011,0011,0101,0110,1001,0001,0010,0000。The results show that: whether uniformlydistributed or non-uniformly distributed the splitter is, the"on-and-off"control is feasible andthe result is obvious. When the switch is in"off"state, the output energy measured of thechannel is almost zero as low as 4^-10 ; When the switch is in"on"state, the minimuminsertion loss is 0.08dB. Finally, with combination of photonic crystal splitting technology andphotonic crystal switch technology, the prospects of controllable photonic crystal beam splitter in the fields of FTTH and CATV are discussed.