Research On Properties And Dynamic Tuning Of Slow Light In Two Dimension Photoniccrystal Waveguide

In recent years, in order to completely break the "electronic bottleneck" in the optical communication systems, achieve all-optical information processing and all-optical switching, all-optical networks have become a research focus. All-optical buffers have been considered as key components for all-optical communications since network throughput, packet loss rate, channel competition of network node, all require optical buffers. Photonic crystal provides us a new and better choice to achieve all-optical buffers. In photonic crystal waveguide, the guided mode is impacted by the strong structure dispersion of photonic crystal; the group velocity would be drastically reduced. Compared to the other slow-light medium, photonic crystal has significant advantages, such as higher potential bandwidth, flexible structure design, small size, easy to integration with existing optics communication devices and tunable,ect. Therefore, optical buffers with slow light photonic crystal can achieve better and more practical optical buffers solution. However, it is important for the optical buffer that the slow light guided mode can be tuned by turned on or turned off, to realize frequency selecting and group velocity controlling. Due to the lack suitable materials and fabrication techniques, so that the research about the dynamic control of slow light mode is of great importance.This paper studied the properties of slow-light photonic crystal waveguide, and focused on the external dynamic modulation of photonic crystal slow-light propagation characteristics. It mainly includes the following parts:Firstly, the basic concept of photonic crystals and characteristics is overviewed. Relevant applications and theoretical research on photonic crystals are introduced. Then, the concept of slow light, the principle of photonic crystal slow-light and the key methods to realizing tunable photonic crystal are presented.Secondly, the photonic band gap calculations of slow light waveguides are introduced. For realizing the dynamic slow light properties, two novel-designed two-dimensional photonic crystal structures are presented and also the related bandgap properties, slow light properties, transmission characteristics with the applied modulation voltage variation are also studied.Thirdly, the potential application of photonic crystal slow light in the future optical interconnects is studied. A Mach-Zehnder electro-optic modulator with small size and high bandwidth is designed in this paper. The design of the modulator, the theoretical analysis of half-wave voltage and modulation bandwidth are presented first; then, the dispersion management of the branch photonic crystal structure is analyzed; also, numerical simulations analysis on its modulation characteristics are done in two different ways.Finally, conclude all the research of the previous section, and give prospects for future work.