# Plotting the polarization ellipse

1. Dec 27, 2012

### patmyer1

Hello,
I am tasked with plotting the polarization state of a laser (basically I've made a polarimeter), but I really have no idea where to go at this point. Below is a sample of the program I have written with some real data that I just took from a laser. I have the intensity profile as a function of the rotational angle of a linear polarizing sheet that I am driving with a motor.

How do I go from the intensity values as a function of the rotational angle of the polarizer to the polarization ellipse plot?

Any help would be doing me a huge favor and would be greatly appreciated.

#### Attached Files:

• ###### Sample data.png
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2. Dec 27, 2012

### Staff: Mentor

Do you know the relation between intensity and amplitude? This way, you get the relation angle/amplitude, which can be plotted with your favorite plotting tool.

3. Dec 27, 2012

### patmyer1

So if I simply take the square root of the intensity value as a function of time I can plot that against rotational angle in a polar plot?

4. Dec 27, 2012

### patmyer1

I also have a quarter wave plate to distinguish between right and left circular polarization, but I am unclear on how to go about that also. This is a project for my work, and I am simply not up to speed on the requisite optics background to finish it is all. Thanks for any help!

5. Dec 27, 2012

### Staff: Mentor

As a function of angle not time, right.

With a quarter wave plate, you could check the direction of rotation of the field - find out if you have more clockwise or more ccw polarized light.