Key Terms

Key Terms

birefringent

refers to crystals that split an unpolarized beam of light into two beams

Brewster’s angle

angle of incidence at which the reflected light is completely polarized

Brewster’s law

$\text{tan}{\theta }_{\text{b}}=\frac{n_2}{n_1}$, where $n_1$ is the medium in which the incident and reflected light travel and $n_2$ is the index of refraction of the medium that forms the interface that reflects the light

corner reflector

object consisting of two (or three) mutually perpendicular reflecting surfaces, so that the light that enters is reflected back exactly parallel to the direction from which it came

critical angle

incident angle that produces an angle of refraction of $90\text{°}$

direction of polarization

direction parallel to the electric field for EM waves

dispersion

spreading of light into its spectrum of wavelengths

fiber optics

field of study of the transmission of light down fibers of plastic or glass, applying the principle of total internal reflection

geometric optics

part of optics dealing with the ray aspect of light

horizontally polarized

oscillations are in a horizontal plane

Huygens’s principle

every point on a wave front is a source of wavelets that spread out in the forward direction at the same speed as the wave itself; the new wave front is a plane tangent to all of the wavelets

index of refraction

for a material, the ratio of the speed of light in a vacuum to that in a material

law of reflection

angle of reflection equals the angle of incidence

law of refraction

when a light ray crosses from one medium to another, it changes direction by an amount that depends on the index of refraction of each medium and the sines of the angle of incidence and angle of refraction

Malus’s law

where $I_0$ is the intensity of the polarized wave before passing through the filter

optically active

substances that rotate the plane of polarization of light passing through them

polarization

attribute that wave oscillations have a definite direction relative to the direction of propagation of the wave

polarized

refers to waves having the electric and magnetic field oscillations in a definite direction

ray

straight line that originates at some point

refraction

changing of a light ray’s direction when it passes through variations in matter

total internal reflection

phenomenon at the boundary between two media such that all the light is reflected and no refraction occurs

unpolarized

refers to waves that are randomly polarized

vertically polarized

oscillations are in a vertical plane

wave optics

part of optics dealing with the wave aspect of light