POLARIZATION OF LIGHT INVESTIGATION of PROPERTIES OF PLANE POLARIZED LIGHT
The purpose of the work:
- to study the method of plane polarized light observation with the help of polaroids;
- to test Malus law, observation of double refraction and interference of polarized rays
Devices and accessories:
1. optic bench;
2. two polaroids;
3. laser;
4. photosensitive device;
5. lens;
6. iceland spar crystal
Task 1. Polarized light testing
1.1. Rotating the analyzer from 0 to 3600 with the step of 100. Write down the readings of device Ù-4316 into table 1.
Table 1
Analyzer rotation angle, j, grad.
Device reading
cos j
cos2 j
Analyzer rotation angle, j, grad.
Device reading
amount of points
mA
amount of points
mA
1.3. Plot the graph of the function in polar coordinate.
Task 2. Malus’s law testing
2.1. Determine the value of trigonometric function and using calculator from 0° to 90°.
2.2. Plot the graph of function I = f (cos2 j) for angles within intervals from 0 to 90°. Task 3. Double refraction observation
3.1. Obtain the first bright spot on the screen turning analyzer. Write down the angle according to the analyzer scale:
= __________.
3.2. Obtain the second bright spot on the screen turning analyzer. Write down the angle according to the analyzer scale:
= __________.
3.3. Determine angles difference:
= __________.
Conclusions
The data of laboratory work fulfilment
Pass mark Signature
Mark of laboratory work defence Signature
questions to be admitted for doing laboratory work and its defending
1. What is the difference between natural and polarized light?
2. What types of polarized light do you know?
3. What are polarization plane and oscillation plane?
4. What methods of polarized light obtaining do you know?
5. What are polarizer and analyzer?
6. What is the principal plane of crystal?
7. What is the difference between the ordinary and extraordinary rays?
8. What is the Nicol prism?
9. Give definition of Malus low.
10. What is the essence of double refraction?
11. What is the essence of Kerr effect?
12. What is the essence of the polarization plane rotation?
13. What are the conditions for interference of polarized rays observation?
14. What are the min and max conditions of polarized rays interference?
QUESTIONS FOR CURRENT TEST PAPERS AND MODULE CONTROL
(theoretical information)
1. Free harmonic oscillations. Differential equation of free harmonic oscillations.
2. Equation and characteristics of free harmonic oscillations.
3. Addition of two oscillations of same frequency in a straight line. Vector diagram method.
4. Addition of two oscillations with nearly equal methods. Beats.
5. Addition of two oscillations acting at right angles. Lissajous figures
6. Damped oscillations. Differential equation of the free damped oscillations and its solution.