Light is a transverse electromagnetic wave and hence can be polarised.
This simulation shows a representation of the electric field of the light.
The user has control over the initial state of polarisation by varying
the amplitude of the horizontal and vertical components of the electric field,
and by changing the relative phase between these two components.
The state of the initial beam can also be set using Stokes Parameters.
Some things to try in the simulation using only the wave setting:
Use the x- and y-amplitude setting to create linear polarised light
at various angle (horizontal, vertical, diagonal).
To understand what is happening here, realise that the x- and y-components of
the wave have a sinusoidal form.
When added together with a phase difference of zero they create a linearly polarised
wave at an angle determined by the amplitudes of the x- and y-components.
Note that they don't interfere as they are perpendicular to each other.
With equal x- and y-amplitudes, now adjust the phase setting.
The phase difference setting causes one component to be delayed relative to the other by the given phase.
This causes elliptical polarisation.
With equal x- and y- amplitudes, see whether the phase difference values are identifiable when
the output wave is linearly polarised (but rotated)
or circularly polarised (appears as a circle in the right figure).
