University Physics Volume 3

# 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
$tanθb=n2n1tanθb=n2n1$, where $n1n1$ is the medium in which the incident and reflected light travel and $n2n2$ 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 $90°90°$
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 $I0I0$ 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