PolarizationPolarization

Slotted WaveSlotted Wave

A string can oscillate in a single plane.A string can oscillate in a single plane.• Transmission axisTransmission axis

Blocking SlotBlocking Slot

The string is blocked if the slot is perpendicular to the The string is blocked if the slot is perpendicular to the motion.motion.

Partial BlockagePartial Blockage If the string is at an If the string is at an

arbitrary angle, part of arbitrary angle, part of the amplitude is the amplitude is blocked.blocked.• Pass component Pass component

parallel to slotparallel to slot

Microwave GridMicrowave Grid

EM waves can be polarized like a string.EM waves can be polarized like a string.• Grid slots must match wavelengthGrid slots must match wavelength

Polarized LightPolarized Light Visible light has a wavelength Visible light has a wavelength

that matches the size of large that matches the size of large molecules.molecules.

Unpolarized light partially Unpolarized light partially passes throughpasses through

Polarized light is blocked Polarized light is blocked based on the angle.based on the angle.

2

0

0

cos

cos

II

EE

Liquid CrystalLiquid Crystal Liquid crystal molecules are Liquid crystal molecules are

long and have electric dipole long and have electric dipole properties.properties.• Polarize light that passes Polarize light that passes

throughthrough

• Respond to electric fieldRespond to electric field

A second polarizer changes A second polarizer changes light to dark.light to dark.

LCDLCD An LCD display uses polarized An LCD display uses polarized

light.light.

An external polarizer can An external polarizer can detect the polarization.detect the polarization.• Tilt angle 90 degressTilt angle 90 degress

LCDs can use color as well.LCDs can use color as well.

ScatteringScattering

Molecules in the air scatter light.Molecules in the air scatter light.

Polarization occurs at an angle from the sunlight.Polarization occurs at an angle from the sunlight.

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