Laser-band Two-dimensional Photonic Crystal With The Structure Of The Numerical Calculation And Design

The photonic crystals (PCs) and the negative refraction characteristic are the currentresearch interests, because they have intensively potential applications in the fields ofoptics and microwave domain. Two-dimensional photonic crystals are paid more attentionfor its easy fabrication, wide applications and various defects that can be incorporated incontrast with three-dimensional photonic crystals. The study on the theory and applicationof photonic crystals and the negative refraction is in unceasing also thorough. But greatefforts should be put into the research on the theoretical analysis, numerical methods andactual applications of photonic crystals and negative refraction. In this thesis, a methodnamed plane wave expansion method (PWE) is introduced; the complete band gaps of thetwo-dimensional triangular lattice and square lattice are studied. The formed mechanism ofthe complete band gaps is explained through the electric field distribution. In the resultanalysis, the triangular lattice is easier to produce the complete band gap than square latticewhen the parameters are same. How to choose to the right parameters to be obtain thelargest complete band gaps is researched. The visible light wave has been used to obtainedconcrete parameters of the two-dimensional triangle lattice theε=13.69 of photoniccrystals. The parameters of the photonic crystals are that cyclical constant a is 237.8 nm,the radius of the hole of air is 107.01 nm .That provide the theoretic basis for designed theTHz two-dimensional photonic crystal. The two-dimensional photonic crystal boardimagery and the negative refraction has been simulated by the way named the finitedifference time domain method, when the operating frequency occupied in the secondenergy bandω=0.3008(2πc/a),the equivalent refractive index is -1. Then thetwo-dimensional photonic crystals board has the function of the imagery. The relation ofthe distance between the physical image and the physical distance has been working out bythe imaging formula L_uv=u+v+d=2d_eff and FDTD method. The research of thetwo-dimensional photonic crystals complete band gaps and the negative refraction has theimportant theory significance and the practical value.