波在匹配介质间的传播

 1 %1D FDTD simulation with a simple absorbing boundary condition
 2 % and a TFSF boundary between hy[49] and ez[50]. 
 3 % dielectric material located ez[100]
 4 SIZE = 400;
 5 LOSS = 0.01;
 6 LOSS_LAYER =250;
 7 ez = zeros(1,SIZE);
 8 hy = zeros(1,SIZE-1);
 9 ceze = zeros(1,SIZE);
10 cezh = zeros(1,SIZE);
11 chyh = zeros(1,SIZE-1);
12 chye = zeros(1,SIZE-1);
13 imp0=377.0;
14 maxTime = 10000;
15 % initialize update coefficient
16 for mm = 1 : 1 : SIZE -1
17     if mm < 100
18         ceze(mm) =  1.0;
19         cezh(mm) = imp0;
20     else if mm < LOSS_LAYER
21         ceze(mm) =  1.0;
22         cezh(mm) = imp0/9.0;
23         else            
24        ceze(mm) =  (1-LOSS)/(1+LOSS);
25        cezh(mm) = imp0 /9/(1+LOSS);
26         end
27         
28     end
29 end
30 for mm = 1 : 1 : SIZE -1
31      if mm < LOSS_LAYER
32        chyh(mm) = 1.0;
33        chye(mm) = 1.0/imp0;
34     else
35         chyh(mm) = (1-LOSS)/(1+LOSS);
36        chye(mm) = 1.0/imp0/(1+LOSS);
37         
38     end
39 end
40 for qTime = 0 : 1 : maxTime
41     % hy(SIZE)=hy(SIZE-1);%
42     
43     % update magnetic field
44     for mm = 1 : 1 : SIZE -1
45         hy(mm) = hy(mm)*chyh(mm) + (ez(mm+1)- ez(mm))*chye(mm);
46     end   
47 % correction for Hy adjacent to TFSF boundary */
48  hy(50)=hy(50)-exp(-(qTime - 30)*(qTime - 30) / 100) / imp0;
49  
50     figure(1);
51     subplot(211);t_hy = plot(hy);    
52     title(‘Magnetic Field‘);  
53     
54     % ABC
55     ez(1)=ez(2);%   
56 %      ez(SIZE)=ez(SIZE-1);%
57 
58     for mm = 2 : 1 : SIZE-1 
59          ez(mm) = ez(mm)*ceze(mm) + (hy(mm)- hy(mm-1))*cezh(mm);
60     end    
61 %     figure(2); 
62     subplot(212);
63     t_ez = plot(ez);
64     title(‘Electric Field‘)
65     ez(51) = ez(51) + exp(-(qTime+0.5-(-0.5)-30.0)*(qTime+0.5-(-0.5)-30.0)/100.0);
66     
67 %     pause(0.01);
68 % %     refreshdata(t_hy);
69 %     refreshdata(t_ez);
70 %     drawnow;
71 end