Characteristics Of One-dimensional Doped Photonic Crystal Twin Defect Modes

Based on Previous studies,in the paper we designed a kind of crystal structure with a neotype defect layer,and studied transmission properties of the crystal structure by the eigen matrix method.Some meaningful results are obtained for the design of related devices.Its main contents are as follows:1.we designed a one-dimensional photonic crystals containing a defect layer,which was made up of positive refractive index material C and negative refractive index material D.when the defect layer materials satisfied the condition:n_+d_+ +n_d_=0,we named it zero average refractivity materials,and viewed the defect layer as a whole;When the condition was not satisfied,the defect layer was considered from two materials.we studied the crystal structure and found that it produced dual defect modes.this finding is a new way of making two-channel filter.2.first of all,we viewed the defect layer as a whole.With the eigen matrix method,we simulated the relation between dual defect modes and the refractive index of defect layer.the conclusions are as follow:when the refractive index of the material C is increased,position, transmissivity and FWHM of dual defect modes are varied in a concave way;when the refractive index of the material D is increased,position,transmissivity and FWHM of dual defect modes are varied in a convex way.3.In the next place,With the eigen matrix method,we simulated the relation between dual defect modes and the width of defect layer,the conclusions are as follow:1) when the thickness of defect layer is increased collectively,the position curve of low frequency defect mode is like a hill,and the high frequency defect mode's is like an anti-sine function image,the transmissivity of dual defect modes is also changed,the transmissivity curve of low frequency defect mode is like a sine function image,and the high frequency defect mode's is like a saddle.2)When the thickness of the material C is solely increased,the position of dual defect layers is red-shifted.On the contrary,the position is blue-shifted when the thickness of the material D is solely increased.And the transmissivity of dual defect modes is changed intricately.