Polarization Flashcards
what does linerearly polarized mean
all waves vibrating in the same direction
what does partially polarized mean
more of the waves are vibrating in one direction than the direction perpendicular
what does 100% polarized mean
all waves vibrating in one direction
what is malus’s law
if 2 polarizers are placed in a beam of light with their directions of pol 90 degrees to each other, no light is transmitted
what is the direction of polarization
the direction of vibration in which the most light is transmitted.
ex. polarizer transmits 80% vibrating in vertical plane and 20% in horiz, direction of pol is vertical
how does light become polarized? 3 thigns
- by passing through a polarizer
- by scattering of light
- be reflectino from the surface of a non-conductive material like glass
in a beam of randomly vibrating waves, how are x and y components related
what is this called
sum of the x components equals sum of y
-beam of light whose waves are resolved into 2 equal components is called UNPOLARIZED OR RANDOMLY POLARIZED
what is an ideal polarizer
transmits 100% of light vibrating in one direction
trasmits 0% of light vibrating PERPENDICULAR direction
what element is circular polarization produced w/
quarter wave plate
-2 vibrations at right angle to each other and a quarter wave out of step
what is brewster’s angle
angle of incidence for which the reflectance in the p vibration is zero => 100% transmitted into the material
- all reflected light in the s direction => 100% linearly polarized light
- reflectance in s vibration is 15%, transmittance is 85%
what is a natural beam of light
electric waves vibrating in all possible directions perpendicular to the direction of travel
where does an oscillating charge radiate its wave
NONE in the direction of oscillation
-VIBRATES in the direction of the oscillating charge
radiates electic waves in the plane perpendicular to its direction of oscillation
what is scattering
single electric wave traveling in the z direction and vibrating in the x direction, encounters charged particles that are set into oscillation in the x direction and radiate electric waves in the y-z plane
- charged particle set into oscillation by an incoming light wave
- particles, in turn radiates light waves as it oscillates
what is the rayleigh scattering
scattering power by small charged particles depends upon the wavelength of the light being scattered
- SMALLLLLL particles compared to wavelenth
- more significant at smaller wavelenths (blue)
why are clouds white
why do they look another color
comprised of large particles in the form of water droplets and they have no preferential scattering as far as wavelength is concerned => white light reaching clouds is scattered as white light
-if they are any other color it is bc they are illuminated with that color
