Polarization I Flashcards
Wave with electric and magnetic fields perpendicular to each other. Transverse wave
Electromagnetic wave
Longitudinal wave
Slinky, parallel
Transverse wave
Perpendicular
Oscillation occurs in a x,y plane perpendicular to the z direction of propagation
Transverse
Polarization is a property of _______ waves that describes their oscillations in (x,y) plane
Transverse
A completely random of waves vibrating in all planes
Unpolarized light
For electromagnetic waves propagating perpendicular to the plane of the paper, the double headed arrows show the vibration plane of the electrical field component for three different states
Polarized light
What are the three different polarization states?
Vertical, horizontal, and diagonal
A dipole with a vertical axis produces _________ polarized light
Vertically
A mixing of polarized and unpolarized waves
Partially polarized light
What are hte 4 fundamental properties of light?
- intensity (amplitude)
- wavelength
- polarization
- coherence
________ describes the directional orientation of the lights electric field in both space and time
Polarization
The vibration of the electric field is confined to a single plane
Plane-polarized light
From the vantage point along the Z axis, the electric field appears to trace a line, so the light may also be said to be _________
Linearly polarized
The electric friend for _________ light has no consistent plane of oscillation
Unpolarized
From the vantage point along the z axis, the electric field for polarized light can look like:
- linearly polarized (vertical)
- elliptically polarized
- circularly polarized
- linear polarized (horizontal)
What defines the polarization type of the light?
The trace of the electric field
Polarization properties of light can be changed by:
- selective absorption
- reflection
- scattering
- birefringance
The _________ selectively transmits all or most of the electric field parallel to its axis, which removing most of the field in the perpendicular direction. Thus the unpolarized light incident on the polarizer is converted into linearly polarized light
Linear polarizer
What does a slit act like as far as polarization goes?
Linear polarization
What happens if you place a 90 degree polarizer over an 180 degree polarizer
Cancel each other
How to calculate how much light is transmitted when there are two polarizer present
Law of malus
Ix=Im[cos^2(theta)]
Measured in amplitude
The first polarizer, transmits 100% of light if the polarization axis is aligned with transmission axis
Polarizer
The second polarizer, analyses the plane polarization properties of the light incident on it.
Analyzer
Direction of polarization can be resolved into what two components?
In the plane of this diagram and perpendicular to it
If a beam of non polarized light is incident on the surface of a smooth, nonconductor such as glass or plastic, the fraction of reflected light will be what?
Will be at least partially polarized
The reflected light is totally polarized (when reflected light is perpendicular to refracted light )
Brewster’s angle
What is the equation for brewsters angle
Tan(thetab)=(n2/n1)
Fresnel’s prediction
0.04 % reflectance
The percentage of incident light reflected from a glass surface. For all angles of incidence except ) and 90, then what?
The reflected light is at least partially polarized
What angle should the transmission axis of a polarized filter be placed in order to reduce these unwanted reflections?
For polarized sunglasses, the transmission axis should be within +/ degrees of vertical (an industry standard)
What does the correct orientation of the polarized filter do?
Effectively removes the reflected sunlight and permits view of the underlying objects
Reflection off water is always _______
Horizontal
Glare from water surface readily passes through the polarized filter whose transmission axis is _______
Horizontal
Glare from water surface blocked by polarized filter whose transmission axis is _____
Vertical
Purpose of antireflective coating
- destruction interference
- reduce glare
- cosmetic
- add polarization too
