A material is birefringent if the
index of refraction
differs for incident electromagnetic waves with different polarizations.
Examples of birefringent media include calcite (CaCO3),
quartz (SiO2), and ice (H2O).
An electromagnetic wave, incident
on a surface can be broken down into two polarization states.
One in which the electric field is polarized perpendicular
to the plane of incidence,
and another which is polarized parallel to the plane of incidence.
Brewster's angle is the
angle of incidence
at which only the component of the electric field polarized normal
to the incident plane is reflected. Hence, if unpolarized light is
reflected of a surface at Brewster's angle, the reflected light
is completely polarized. Brewster's angle occurs when
the angle between the reflected and refracted rays are 90 degrees.
Named for
Sir David Brewster
who discovered it empirically.
Diffraction, the deviation of light from rectilinear
propagation, is a characteristic of wave phenomena which
occurs when a portion of a wave front is obstructed in some way.
When various portions of a wave front propagate past some obstacle,
and interfere at a later point past the obstacle, the pattern formed
is called a diffraction pattern.
The dependence of the velocity of a wave on the frequency of
the wave is known as dispersion. A media in which waves
of different frequencies propagate at different speeds
is said to be dispersive.
Each point on a propagating wave can be considered as the
source of a small wave, or wavelet which propagates at the same speed as the original wave.
The new wave front for the propagating wave can be constructed by drawing
a line tangent to the edges of these wavelets.
The intensity of a light wave, commonly denoted by the letter I.
The irradiance is the power per unit area carried by an electromagnetic
wave. The time averaged value of the magnitude
of the Poynting vector.
The index of refraction is the ratio of the speed an electromagnetic
wave in vacuum to the speed of the electromagnetic wave in
a particular medium. typically denoted by the lowercase
n. n = c/v. The index of refraction is a property of
the medium in question, and the incident electromagnetic wave.
In general, they index of refraction may depend on on the
frequency of the incident wave, and on its polarization.
A media in which the index of refraction depends on the
frequency of the electromagnetic wave is said to be
dispersive.
A media in which the index of refraction depends on the
polarization of the incident wave is said to be
birefringent
Commonly denoted by the letter S.
S = (1/mu0) E x B. The Poynting vector
represents the flux of energy density per unit time through
a unit area.
The time averaged value of the
Poynting vector is the irradiance.
Named after John Henry Poynting
Also known as harmonic waves. Any wave form can be broken down into
a combination of simpler waves which are sinusoidal. These sines and cosines
are known as simple harmonic waves.
