西邮科技光学课程设计报告 - 图文

r2=sqrt(R2R);

f=(4*pi*q*cos(j1))./w; A=r1.^2+r2.^2;

B=1+(r1.^2)*(r2.^2); C=2*r1*r2.*cos(f); R1=(A+C)./(B+C); R=R1/100;

plot(w,R,'r') hold on

j0=pi/6;

j1=asin((n0*sin(j0))/n1); f=(4*pi*q*cos(j1))./w;

r1s=-(n1*cos(j1)-n0*cos(j0))/(n1*cos(j1)+n0*cos(j0)); r1p=(n1/cos(j1)-n0/cos(j0))/(n1/cos(j1)+n0/cos(j0)); R1s=r1s.^2; R1p=r1p.^2;

R1R=(R1s+R1p)/2; r1=sqrt(R1R);

j2=asin((n1.*sin(j1))./n2);

r2s=(n1*cos(j1)-n2*cos(j2))/(n1*cos(j1)+n2*cos(j2)); r2p=(n2/cos(j1)-n1/cos(j2))/(n2/cos(j1)+n1/cos(j2)); R2s=r2s.^2; R2p=r2p.^2;

R2R=(R2s+R2p)/2; r2=sqrt(R2R);

f=(4*pi*q*cos(j1))./w; A=r1.^2+r2.^2;

B=1+(r1.^2)*(r2.^2); C=2*r1*r2.*cos(f); R1=(A+C)./(B+C); R=R1/100;

plot(w,R,'g') hold on

j0=40*pi/180;

j1=asin((n0*sin(j0))/n1); f=(4*pi*q*cos(j1))./w;

r1s=-(n1*cos(j1)-n0*cos(j0))/(n1*cos(j1)+n0*cos(j0)); r1p=(n1/cos(j1)-n0/cos(j0))/(n1/cos(j1)+n0/cos(j0)); R1s=r1s.^2;

R1p=r1p.^2;

R1R=(R1s+R1p)/2; r1=sqrt(R1R);

j2=asin((n1.*sin(j1))./n2);

r2s=(n1*cos(j1)-n2*cos(j2))/(n1*cos(j1)+n2*cos(j2)); r2p=(n2/cos(j1)-n1/cos(j2))/(n2/cos(j1)+n1/cos(j2)); R2s=r2s.^2; R2p=r2p.^2;

R2R=(R2s+R2p)/2; r2=sqrt(R2R);

f=(4*pi*q*cos(j1))./w; A=r1.^2+r2.^2;

B=1+(r1.^2)*(r2.^2); C=2*r1*r2.*cos(f); R1=(A+C)./(B+C); R=R1/100;

plot(w,R,'b') hold on

j0=50*pi/180;

j1=asin((n0*sin(j0))/n1); f=(4*pi*q*cos(j1))./w;

r1s=-(n1*cos(j1)-n0*cos(j0))/(n1*cos(j1)+n0*cos(j0)); r1p=(n1/cos(j1)-n0/cos(j0))/(n1/cos(j1)+n0/cos(j0)); R1s=r1s.^2; R1p=r1p.^2;

R1R=(R1s+R1p)/2; r1=sqrt(R1R);

j2=asin((n1.*sin(j1))./n2);

r2s=(n1*cos(j1)-n2*cos(j2))/(n1*cos(j1)+n2*cos(j2)); r2p=(n2/cos(j1)-n1/cos(j2))/(n2/cos(j1)+n1/cos(j2)); R2s=r2s.^2; R2p=r2p.^2;

R2R=(R2s+R2p)/2; r2=sqrt(R2R);

f=(4*pi*q*cos(j1))./w; A=r1.^2+r2.^2;

B=1+(r1.^2)*(r2.^2); C=2*r1*r2.*cos(f); R1=(A+C)./(B+C); R=R1/100;

plot(w,R,'k') hold on

j0=pi/3;

j1=asin((n0*sin(j0))/n1); f=(4*pi*q*cos(j1))./w;

r1s=-(n1*cos(j1)-n0*cos(j0))/(n1*cos(j1)+n0*cos(j0)); r1p=(n1/cos(j1)-n0/cos(j0))/(n1/cos(j1)+n0/cos(j0)); R1s=r1s.^2; R1p=r1p.^2;

R1R=(R1s+R1p)/2; r1=sqrt(R1R);

j2=asin((n1.*sin(j1))./n2);

四．实验结果及结果分析

仿真图

分析

1. 从图中我们可以看到，当n1=n0或者n1=n2时，R和未镀膜的反射率R0是一样的。而当n1＜n2的时候，R＜R0，在λ/4时反射率最小。此时的单层膜具有增透的效果，称为增透膜。当n1＞n2时，R＞R0，在λ/4时反射率最大。此时的单层膜具有增反的效果，称为增反膜。

2，从图中我们可以看出来，当波长一定的时候，入射角越大，那么反射率越大。同时反射率极小值位置向短波方向移动。另外，当入射角一定的时候，波长越长，那么反射率越大。 小结

第一个程序并不是太过困难，我们只是逐一的将各个薄膜折射率分开进行编程，最后汇总就可以了。通过查询Matlab书籍，我们也了解到了如何给图形加标注，改颜色等技巧。而第一个试验中，我们要了解了正入射时候的单层膜反射率公式即可。第二个程序中所遇到的问题便是，当入射光不是正入射的时候，我们便要用公式进行推导，将不是正入射时候的反射率公式推导出来。做完这个步骤以后，固定各个折射率，逐一输入各个不同的入射角，最后进行汇总即可。其中便是要我们了解到自然光的 s分量和p分量，求出其平均值，再代入单层膜的反射率R公式： R=(r12+r22+2*r1*r2*cosφ)/(1+r12*r22 +2*r1*r2*cosφ),即可算出不同入射角情况下的反射率。