Quater wave plate and half wave plate.pptx

Quater wave plate and half wave plate

1. The interference of polarized light Quarter and Half wave plate peer team by Mukesh.I Sivaram.G 1st

2. What is Ordinary and Extraordinary ray ? Ordinary ray obeys the laws of refraction where as the Extraordinary ray does not obey the laws of refraction O-ray travels with same speed in all directions of the crystal where as E-ray travels with different speed along different directions =  

3. What is wave plate ? A  waveplate  or  retarder  is an  optical device that alters the  polarization  state of a  light wave travelling through it. 

4. What is Quarter wave plate ? When the path difference between the ordinary ray and extraordinary in a crystal is  

5. let us consider a negative calcite crystal with its optic axis is parallel to its surface . A beam of monochromatic light of wavelength λ is incident normally on the crystal surface . It is broken up into ordinary and extraordinary waves inside the plate both of these waves travel in the same direction but with different velocities The velocity of Extraordinary ray is larger than Ordinary ray since Ve > Vo , in a negative crystal so there is path difference between them .  

6. Let t be the thickness of the plate . The optical paths of the ordinary and extraordinary waves in the plates are . The path difference between the two waves on emerging = ( )t ……. (1) The path difference of the quarter wave plate = ….... (2)  

7. From equation (1) and (2) ( )t = t = , for negative calcite crystal. For a positive crystal such as quartz , For a negative crystal such as quartz ,  

8. What is Half wave plate ? When the path difference between the ordinary ray and extraordinary in a crystal is  

9. let us consider a negative calcite crystal with its optic axis is parallel to its surface . A beam of monochromatic light of wavelength λ is incident normally on the crystal surface . It is broken up into ordinary and extraordinary waves inside the plate both of these waves travel in the same direction but with different velocities The velocity of Extraordinary ray is larger than Ordinary ray since Ve > Vo , in a negative crystal so there is path difference between them .  

10. Let t be the thickness of the plate . The optical paths of the ordinary and extraordinary waves in the plates are . The path difference between the two waves on emerging = ( )t ……. (1) The path difference of the half wave plate = ….... (2)  

11. From equation (1) and (2) ( )t = t = , for negative calcite crystal. For a positive crystal such as quartz , For a negative crystal such as quartz ,  

12. Comparison Attribute Half Wave Plate Quarter Wave Plate Path difference λ/2 λ/4 Phase difference π π/2

13. Uses of Quarter and Half wave plates : Quarter-waveplates are used to turn linearly polarized light into circularly polarized light and vice versa. A half-wave plate is used as a polarization rotator, flipping the polarization around the fast axis.

14. Thanks for the attention The difference between ordinary and extraordinary is that little extra