# Geometric Optics: Mooney Rhomb

1. Nov 13, 2008

### andrewm

1. The problem statement, all variables and given/known data

A Mooney rhomb is a quadrilateral prism that converts linear light to circular polarized light. The question is here:

http://books.google.ca/books?id=SL1...hl=en&sa=X&oi=book_result&resnum=1&ct=result"

2. Relevant equations

Trigonometry. Snell's law.

3. The attempt at a solution

Total internal reflection must occur at the edge of the rhomb. The total phase change due to TIR must be pi/4. But there are too many equations, and too few constraints!

Last edited by a moderator: Apr 23, 2017
2. Sep 29, 2010

### Dalimatt03

I think the Mooney Rhomb accomplishes the same feat as the Fresnal rhomb.
But, here is the equation to find the difference in the angle between the S and P polarization:

tan(del/2)=cosA*sqrt(sin^2(A)-(nt/ni)^2)/sin^2(A)

Where A is the incident angle, nt is transmitted index, ni is incident index, and del is the phase difference produced between the two types of polarizations.

For the Mooney Rhomb there are two TIR's and each needs to produce pi/4 phase difference for circularly polarized light to be produced.

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