Fresnel reflection coefficients for isotropic or birefringent media
[rte,rtm] = fresnel(na,nb,theta)
3-d vectors of refractive indices of left and right media, e.g., na=[na1,na2,na3]
array of incident angles from medium a (in degrees) at which to evaluate rho's
reflection coefficients for TE and TM polarizations
fresnel(na,nb,theta) computes Fresnel reflection coefficients for isotropic or birefringent media
The function assumes that the interface is the x-y plane and that the plane of incidence is the x-z plane, with the x,y,z axes being the diagonal optical axes where x,y are ordinary axes and z, extraordinary. TE or s-polarization has E = [0,Ey,0], and ordinary indices na(2) or nb(2) on either side. TM or p-polarization has E = [Ex,0,Ez], and theta-dependent refractive index, e.g., 1/Na^2 = cos(th)^2/na(1)^2 + sin(th)^2/na(3)^2
na,nb can be entered as 1-d, 2-d, or 3-d (row or column) vectors according to the cases: (1) isotropic na = [na] in all cases, na,nb are na = [na;na;na] (2) uniaxial na = [nao,nae] ==> turned into 3-d column ==> na = [nao;nao;nae] (3)biaxial na = [na1,na2,na3] vectors internally na = [na1;na2;na3]
theta = 0:1:90; [rte,rtm] = fresnel(1, 1.5, theta); [rte,rtm] = fresnel(1, [1.8,1.5], theta); [rte,rtm] = fresnel([1.8,1.5], 1.5, theta); [rte,rtm] = fresnel([1.8,1.5], [1.5,1.9], theta); [rte,rtm] = fresnel([1.5,1.8,1.5], [1.5,1.9], theta);