# I Circularly polarized light through a polarimeter

1. Aug 26, 2016

### lcr2139

What happens when circularly polarized light goes through a polarimeter? In my experiment the polarimeter is made up of two crossed PEMs and a polarizer.

2. Aug 26, 2016

### lcr2139

Also, what about linearly polarized light?

3. Aug 26, 2016

### lcr2139

how does the angle of the polarizer fit in to this problem?

4. Aug 26, 2016

### drvrm

Interestingly, a monochromatic linearly polarized light beam can be considered as a superposition of two circularly polarized electromagnetic waves that are propagating in the same direction with the same frequency but the opposite sense of rotation. see the animation of circularly polarized light ..........

see the details<http://ja01.chem.buffalo.edu/~jochena/research/opticalactivity.html> [Broken]
it may help...

Last edited by a moderator: May 8, 2017
5. Aug 26, 2016

### Andy Resnick

What kind of polarimeter/ellipsometer? Also, what is a PEM?

6. Aug 26, 2016

### lcr2139

a polarizer is made up of 2 PEMs and a polarizer. It is not a single optical element. A PEM is a photoelastic modulator.

7. Aug 26, 2016

### nasu

The first part is probably a typo. If a polarizer includes a polarizer, you will have an infinite regression. :)
But what do you mean by crossed PEMs?

8. Aug 26, 2016

### lcr2139

crossed PEMs mean that one is at 0 degrees and the other is at 45 degrees.

9. Aug 26, 2016

### blue_leaf77

If you know how a linearly polarized light is affected by a polarimeter, extending it to circularly polarized light is not too difficult.

Last edited: Aug 26, 2016
10. Aug 26, 2016

### nasu

What feature of the PEM is at these angle?

11. Aug 29, 2016

### Andy Resnick

Zoiks... sounds complicated.

Well, the easiest way to proceed is to write out the Jones matrix for the instrument. I'm not sure what the Jones matrix is for an oriented PEM, but my guess is that it is similar to an elliptic retarder

http://spie.org/Publications/Proceedings/Paper/10.1117/12.429559