# Double Refraction

If you are searching about what is refraction ? Then here is the complete information about this topic .You can also check the article in which i share about  about Diffraction .The direction in which the transmitted light beam does not withstand dual refraction inside the crystal is known as the optic axis.If only one optic axis is present in a crystal, then it is called uni-axial crystal. On the other hand if two optic axes are present in a crystal, it is known as biaxial crystal.

 Double Refraction

#### Define Double Refraction

When a uni-polar beam of light passes through an azeotropic crystal such as quartz or calcite, the beam will split into two refracted beams. This is called double refraction or birefringence. Double reaction is also known as birefringence.

The given diagram shows double refraction in calcite crystals. Refracted beams are polarized to the plane. One beam is polarized along the direction of the optic axis and is known as an extraordinary ray (e-ray), while the other refracted beam is polarized along the direction perpendicular to the optic axis and is called an ordinary beam ( O-ray).

## Explain double refraction

The wave fronts of E-rays and O-rays are shown for quartz and calcite crystals in the given image. The speed of an O ray is the same in all directions of a crystal, while an extraordinary ray travels with different speeds in different directions. The speeds of the O-rays and the E-rays are the same along the optical axis. The speed of an E ray is less than that of an O ray in a quartz crystal, it is a positive crystal. The speed of an E ray is higher than that of an O ray in a calcite crystal, it is a negative crystal. In addition to the optical axis, the refractive index μe = μ0. Then, the wavefront of the E and O rays will coincide. Quartz crystals in μe> μo in all other directions, and it is much larger in the direction perpendicular to the optical axis. Crystalline crystallizes in the rhombohedral (trigonal) crystal system. The diagonal line through the oblique corners is the optical axis. Calcite μe <μo in all directions except the optical axis. Then, the speed of ray E is greater than that of ray O. The value is too low in the direction perpendicular to the optical axis.

 double refraction diagram

#### Application of double refraction

Double refraction is used in
1.It is used in many optical devices.
2.It is used in Liquid crystal displays.
3.It also find application in the most common type of flat panel display.
4.It  also plays an important role in second harmonic generation.
5.It is also used in nonlinear optical components.

### Phenomenon of double refraction

Double refraction is a phenomenon by a ray of light, when it collides with a fierce substance, is divided by polarization into two rays which take slightly different paths. First this effect was first explained in 1669 by Danish scientist Rasmus Bartholin,

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