What is an extraordinary ray?
Definition of extraordinary ray : the part of a ray divided in two by double refraction that does not follow the ordinary laws of refraction because its speed varies with its direction in the doubly refracting medium.
What is ordinary and extraordinary refractive indices?
In a birefringent crystal, the incident light gets split into two beams. The ordinary ray experiences constant refractive index n_o but the extraordinary ray experiences refractive index that varies with the direction of propagation of the light in the crystal.
What are ordinary and extraordinary rays in a uniaxial crystal?
A crystal which has only one optic axis is called uniaxial crystal. A crystal which has only two optic axis is called biaxial crystal. The refractive index of the ordinary ray is constant for any direction in the crystal, and of the extraordinary ray is variable and depends on the direction.
What is called ordinary ray?
Definition of ordinary ray : the part of a ray divided in two by double refraction that follows the ordinary laws of refraction because its speed is the same in all directions through the doubly refracting medium.
Is the ordinary ray the fast ray?
In most cases the refractive indices for the two rays produced by double refraction are not the same. One of the two rays will have a higher refractive index (and a lower velocity); this ray is called the slow ray. The other ray is then the fast ray. Ordinary light is not polarized.
What is extraordinary polarization?
Light polarized along the optic axis is called the extraordinary ray, and light polarized perpendicular to it is called the ordinary ray. These polarization directions are the crystal principal axes.
What is ordinary refractive index?
The ordinary ray will always experience a refractive index of no, whereas the refractive index of the extraordinary ray will be in between no and ne, depending on the ray direction as described by the index ellipsoid.
What is the speed of e-ray and O ray along the optic axis?
The E-Ray travels faster than O-Ray except along the Optic axis. The spherical O-Wavefront is entirely within the ellipsoidal E -Wavefront. Positive crystals are crystals in which refractive for O-Ray is less than that for E-Ray( 0< ). The velocity of O-Ray is greater than or equal to the velocity of E-Ray.
What happen if o-ray and e-ray travel along the optic axis?
The velocity of e-ray is less than that of o-ray in quartz crystal, this is a positive crystal. The velocity of e-ray is more than that of o-ray in calcite crystal, this is a negative crystal. Along the optic axis, the refractive index μ e = μ 0. So the wave fronts of e-ray and o-ray will coincide.
What happens to ordinary and extraordinary rays?
double refraction One ray (called the extraordinary ray) is bent, or refracted, at an angle as it travels through the medium; the other ray (called the ordinary ray) passes through the medium unchanged.
In what way do ray and O-ray differ?