Research On The Enhancement Of Silicon Photonic Crystal Band Gap

The development of silicon photonics makes it possible to break the bottleneck of microelectronic technology.Silicon photonic crystal takes an important part in silicon photonics.Applying the unique band gap characteristic of photonic crystal can profoundly improve the performance of silicon photonic devices and the density of integration.Therefore,the enhancement of band gap is an important content in the research of silicon photonic crystals.In this thesis,firstly,we study the photonic crystals based on the cylindrical rods and connected veins,which is divided into three categories: the photonic crystal based on the cylindrical rods and cross-connected veins,the photonic crystal based on the cylindrical rods and oblique-crossing connected veins,and the photonic crystal based on the cylindrical rods and diagonally connected veins.In order to obtain the optimized normalized bandwidth,the influences of the radius of the rods and the width of the veins are investigated.Also,under the condition of fixing the filling ratio,the normalized bandwidths changing with the structural parameters are discussed.Then,a two-dimensional complex photonic crystal with copper-coin rods and veins in square lattice is proposed.The effects of structural parameters on the photonic band gap property are discussed.The width of the veins,the radius of the rod,the size and orientation of the square hole are optimized.The two-dimensional photonic crystal with complex unit cell in square lattice is compared with the two-dimensional photonic crystal with copper-coin unit cell in square lattice.At last,we further analyzes the photonic crystals based on the cylindrical rod with holes,which are divided into four categories,the photonic crystal based on the cylindrical rod with one hole,the photonic crystal based on the cylindrical rod with two holes,the photonic crystal based on the cylindrical rod with three holes and the photonic crystal based on the cylindrical rod with four holes.The effects of the number of the symmetric axes on the photonic band gap property are discussed.In conclusion,we proposes several new types of photonic crystal structures and optimizes them in this thesis.The results give an effective method to obtain large normalized bandwidths of the silicon photonic crystals and provide the theoretical foundation for the design of high performance silicon photonic crystal microcavity,waveguide and filtering devices,etc.