Lab 12. Polarization of Light

Introduction

     In this experiment, we observed the change in light intensity of light passing through crossed polarizing filter, which remove all but electric fields. This experiment focuses only on the electric field variation. We also measured the transmission of light through two polarizing filters as a function of the angle between their axes and compare it to Malus's Law.

Preliminary Questions

1. When one filter is at right angles to the other filter, anything can be seemed through both filters. 
2. When two filters' axes were parallel to each other, increasing of angle(0° - 180°) will give the increasing of transmitted light intensity. 

Procedure

PART 1. Two polarizers

Set two polarizers to be parallel to each others (0° & 0°), and rotate the second polarizer only with ~7.5° clockwise direction and measure the light intensity.

PART 2. Three Polarizer

Set first and third polarizers to be parallel to each others, and rotate the second polarizer by 7.5° clockwise direction and record the light intensity.

Data

PART 1.

PART 2. 

Discussion/Analysis

PART 1.

     1. 

2. 

3. 

4. When two polarizers were parallel to each other, the minimal lights were passing through. Therefore, the intensity would be minimal as well, which close to zero. Whereas, when two polarizers were perpendicular to each other, the maximal lights were passing through; which allowed maximum intensity. The measurement of part 1 started with perpendicular axis of two polarizer; so that it showed highest values of intensity. 

PART 2. 

1 & 2. 

3. 

Polarization upon Reflection

1. The light from the fluorescent bulb does not have any polarization. 

2. The reflected light have polarization. The light will be polarized in parallel plane.