Polarization of Light

F21偏光與布魯斯特角(20150527) F21偏光與布魯斯特角(20150826)

Item no.: F21

Introduction

The electromagnetic waves consisting of most common light source, such as Sun or laser ray might have its oscillation in different plane by turn as it travel toward specified direction (unpolarized light). Of course, we also might use a polarizer to change the mean distribution of light energy i.e., the intended component of incident ray (polarized light) will be allowed to pass through while the other components are left to be filtered.

Objectives
  • Malus’ Law of Polarization
  • Brewster’s angle
Experiment—Law of Malus

As a completely plane polarized light is incident on the analyzer, the intensity I of light transmitted to analyzer is directly proportional to the square of cosine of angle between the transmission axes of the analyzer and polarizer.

Experiment—Brewster’s angle

When an unpolarized light reflects off a nonconducting surface, it is partially polarized parallel to the plane of the reflective surface. There is a specific angle, θ1 , called Brewster’s angle at which the reflected ray and the refracted ray are 90 degrees apart and the light energy parallel to reflected plane will disappear.

As unpolarized light is sent at Brewster’s angle into a series of glass sheets, electric field vector of refracted ray will become weaker due to the component perpendicular to incident plane might be partially disappear.

實驗項目:
  1. 馬魯斯定律
  2. 布魯斯特角
實驗器材:
  1. 測光計 x1
  2. 鋁製實驗平台 x1
  3. 鋁製滑塊固定座x2
  4. 二極體雷射與起偏器x1
  5. 檢偏器與可旋轉懸臂x1
  6. 可旋轉待測物平台x1
  7. 載玻片 x10