Re: POLARIZATION

[LUDWIK KOWALSKI <KOWALSKIL@alpha.montclair.edu>]

On 25 May 1998  Quist, Oren <QuistO@mg.sdstate.edu> wrote:

> Speaking of polarization....   Does anyone out there have a "meaningful"
> experiment, for the advanced undergraduate lab, on circular polarization?   
  
I do not know what you mean by meaningful. Here is what you can do. Take 
a laser producing a polarized beam. Give students polarizing sheets and 
ask for a demonstration that the light is polarized. Then place a "quoter
wave" plate at the output of the laser and again ask about the state of 
polarization.

Most likely your "quater wave" plate will not be a quoter wave for your  
wavelength and for that reason the light will be polarized eliptically,
rather than circularly. Unless students are familiar with elliptical
polarization they will probably say that the light is partially polarized.
How to distinguis 100% elliptical polarization from partial polarization?
Or how to distinguish circularly polarized light from nonpolarized light,
if your plate matches the wavelength of your laser?

A cook-book answer to this question can be found in many optics textbooks. 
You can guide students through the "discovery method" but I am not sure 
how to proceed to make this meaningful. It can be a very long activity,
unless many "hints" are provided. Too many hints and you are back to the
cook-book method. 
                               Ludwik Kowalski