BSA Flow Software Installation and User's Guide - CSI

Figure 7-31: Reflection and refraction at an interface (drawn for air-water).
The angles of the reflected and the transmitted light, ϕ r and ϕ t , are related to
the angle of incidence, ϕ i , and the refractive indices, n 1 and n 2 , by the two
equations:
ϕr =−ϕi
and
(A1-1)
n sin ϕ = n sin ϕ
(A1-2)
1 i 2 t
Here, the angles ϕ i , ϕ r and ϕ t all lie in the same plane of incidence, which
contains the incident ray and the normal to the interface in the point of
incidence.
In the following calculations it is assumed that the materials involved are
completely dielectric (non-conductive). Thus, the refractive indices n 1 and
n 2 have only real terms. This means that if the incident light is polarized
either perpendicular or parallel to the plane of incidence, the transmitted
light is polarized in the same orientation.
It should be pointed out that the amplitude of the transmitted light is
polarization dependent. Therefore, if the incident light is polarized in
another orientation, the polarization of the transmitted light will, as a rule, be
rotated.
Critical angle When the incident light comes from the denser side of the interface
(n 1 > n 2 ), there is a critical angle of incidence above which no light is
transmitted (total reflection):
BSA Flow Software:Reference guide 7-35