# Angle of transmission past brewster's angle

1. Sep 18, 2015

### lcr2139

1. The problem statement, all variables and given/known data
find TM p-parallel for (angle of incidence)=68 degrees, n(sub1) = 1.0, n(sub2) = 1.6

2. Relevant equations
how to find angle of transmission, theta(sub)i

3. The attempt at a solution
I know that when the angle of incidence is greater than the critical angle, all the light undergoes reflection. I have to use TM p-parallel equations. I know that using Brewster's angle, the angle of refraction is 90 degrees. How do I find the angle of transmission?

2. Sep 18, 2015

### DEvens

3. Sep 18, 2015

### lcr2139

I am sorry but this does not answer my question. It only goes from lower than brewster's angle to brewster's angle. I am looking for an angle greater than brewster's angle. Can you help me?

4. Sep 18, 2015

### blue_leaf77

The question sounds a bit vague to me, are you asked to calculate the magnitude of the transmitted TM component? Then there is Fresnel equations as your machinery.
This part of the post should be allocated for the required equation to calculate the angle of transmission.

5. Sep 18, 2015

### lcr2139

I know I need to use fresnel's equations. My question is, how do I calculate the angle of transmission if it is greater than brewster's angle? Meaning, the angle of transmission is purely reflected.

6. Sep 18, 2015

### blue_leaf77

There are few things we need to correct before proceeding.
No, it is not. When the angle of incidence is equal to the Brewster angle, it's the sum of the incident and refracted angles which forms 90 degree.
The total reflection only occurs for the case of internal reflection where the refractive index of the second medium is greater than the first medium. So, in your problem, total reflection will never be observed.
When you have a ray (forget the polarization) coming to the interface between two media given the refractive indices and angle of incident, there is this equation you will always use to find the refracted angle. Try to go back in your mind to your highschool times to figure out this equation, if this does not work try googling "refraction".