Research On Photonic Crystal Waveguide Slow Light Dynamic Control Characteristics

In present optical communication system, electrical devices' limitation restricts the development of optical networks. All-optic network is the future of optical communication, but its key component: optical buffer is not available. Slow light is one solution. Comparing with traditional slow light methods, photonic crystal waveguide slow light technology has its advantages:it can produce slow light in room temperature and in almost any frequency, do not need specious material, and can easily control the speed of slow light.In this thesis, the research is focused on slow light dynamic control characteristics and limitation of photonic crystal band gap. The main works and innovative results are listed as follow:(1) Here we design the calculation method for group velocity dispersion, and calculate group velocity dispersion of defect mode from group velocity simulated by previous simulation. After compare group velocity dispersion when defect mode moves and not, it is find that the movement of defect mode makes the group velocity dispersion change.(2) Two methods for control slow light in defect mode:moving line defect, turning reflective index of two materials, are both failed. We find both of them can't make defect mode move. So it comes to that the speed of slow light is determined by the frequency of defect mode. (3) In the article, it is proposed the factors which affect the control speed of slow light velocity in the dynamic control process. After decompose slow light velocity on the time of the partial derivatives step by step in mathematics, and though theoretical analysis and simulation, we get these factors. After remove the contradictory factors to the design of slow light, we finally get optimal design:faster speed of the media response, higher order defect mode, rational structure of photonic crystals.(4) Comparing electronic devices encountered in electronic tunneling effect, small photonic crystal devices inevitably appears "photon tunneling" effect. This is because photonic crystal lattice constant is fixed and can only reduce the number of cycles to make photonic crystal small, which gives a chance to penetrate the photonic band gap. After simulation, we find that higher reflective index can lower the chance, the type of photonic crystal lattice has great influence in the chance, and the radius of material has no effect in it.