Experiment 12: Polarization of Light

Objective:
Observe how light intensity varies through polarizing filters set at predetermined angles.

Equipment:
-Computer
-Logger pro
-Light sensor
-Light source
-3 polarizing filters

Procedure:

Two polarizers:

We set up a system of two polarizers with the light source on one side and the light sensor on the other. We turned the second polarizer to its 90 degree mark and adjusted the first polarizer until the light going through both was as dark as possible, this should occur when the two polarizer axes are perpendicular to each other and assumed the intensity value was as close as possible to zero. We then returned the second polarizer to 0 degrees so that both were parallel and we took intensity measurements in intervals of 7.5 degrees for the second polarizer until we reached a quarter revolution. We then reversed this process and collected further data and created a graph using loggerpro.

Data/Calculations:

two polarizers:

three polarizers:

since the axis for the first and third polarizers are 0 and 90 respectively the intensity will be maximum when the central polarizer is 45 and will be minimum when the central polarizer is either 0 or 90

polarization upon reflection:
- the light from the florescent bulb is unpolarized
- the light in the plane is perpendicular to the light in the table is polarized

Conclusion:
The observed patterns in each case demonstrated how the intensity varies sinusoidally when rotating a polarizer with respect to a light source.