pwm法计算二维光子晶体能带的通用程序.docVIP

function PBGBand(ea,eb,R,PCType,Keach,TEorTM) %function PBGBand(ea,eb,R,PCType,Keach,TEorTM) %-------------------------------------------------------------- %| This is a program to calculate the Photonic Bands of two | %| dimension Photonic Crystal with circular inclusions. | %| It calculates both TE and TM modes (E and H polarization) | %-------------------------------------------------------------- %Parameters: %ea: The dielectric constant of the circular inclusions. %eb: The dielectric constant of background. %R: The radius of dielectric columns %PCType =1: Square lattice % =2: Triangular lattice % =3: Honeycomb %Keach: The number of k vectors in each wave vector branch. %TEorTM: =0: TE modes % =1: TM modes %-------------------------------------------------------------- tic; TEorTM=1; PCType=2; Keach=6; R=0.3; ea=1; eb=10.5; disp(--------------------------------------------------) if (TEorTM==0) disp(Plane wave expansion method for PC bands: TE modes); else; disp(Plane wave expansion method for PC bands: TM modes); end disp(--------------------------------------------------) if (PCType==1) disp(Square lattice); end if (PCType==2) disp(Triangular lattice); end if (PCType==3) disp(Honeycomb lattice); end %Control parameters Ktype=3; % The number of band parts, such as X-M, T-X, ... NumberK=Ktype*Keach; %The total number of K vector; NEIG=20; %NEIG: The number cut of the Eigvalue. %Initial parameters a=1; %Lattice constance. a1=a*[1,0]; if PCType==1 a2=a*[0,1]; end if PCType==2 a2=a*[0.5,sqrt(3)/2]; end %a1,a2 are the basic vectors of lacctice cell. ac=abs(a1(1)*a2(2)-a1(2)*a2(1)); %ac: Area of lattice cell. b1=2*pi/ac*[a2(2),-a2(1)]; b2=2*pi/ac*[-a1(2),a1(1)]; %b1, b2 are vectors in reciprocal space. f=pi*R*R/ac; %f: The filling fraction, i.e. the fraction of % the total volume occupied by the rods. MaxDimForG=12; % The max Potive Number of the reciprocal lattice, G DimForG=2*MaxDimForG+1; NPW=DimF