Polarization

= = flat = = =Learning Outcomes=



=Unploarised Light=

 A light wave that is vibrating in more than one plane is referred to as  **unpolarized light** . Light emitted by the sun, by a lamp in the classroom, or by a candle flame is unpolarized light. Such light waves are created by electric charges that vibrate in a variety of directions, thus creating an electromagnetic wave that vibrates in a variety of directions.

Polarised Light
It is possible to transform unpolarized light into **polarized light**. Polarized light waves are light waves in which the vibrations occur in a single plane. The process of transforming unpolarized light into polarized light is known as **polarization**. There are a variety of methods of polarizing light. The four methods discussed on this page are:
 *  [|Polarization by Transmission]
 *  [|Polarization by Reflection]
 *  [|Polarization by Refraction]
 *  [|Polarization by Scattering]

Polarization
@http://tutor-homework.com/Physics_Help/polarized_light.html

Simulations
**//Optics//**
 * [|Radio Waves and EM Fields] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/PhET/Images/radio-waves-screenshot.png width="300" height="200" link="http://www.cabrillo.edu/~jmccullough/Applets/PhET/radio-waves_en.jar"]] || Broadcast radio waves from KPhET. Wiggle the transmitter electron manually or have it oscillate automatically. Display the field as a curve or vectors. The strip chart shows the electron positions at the transmitter and at the receiver. ||
 * [|Color Vision] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/PhET/Images/color-vision-screenshot.png width="300" height="200" link="http://www.cabrillo.edu/~jmccullough/Applets/PhET/color-vision_en.jar"]] || Make a whole rainbow by mixing red, green, and blue light. Change the wavelength of a monochromatic beam or filter white light. View the light as a solid beam, or see the individual photons. ||
 * [|Geometric Optics] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/PhET/Images/geometric-optics-screenshot.png width="300" height="200" link="http://www.cabrillo.edu/~jmccullough/Applets/PhET/geometric-optics_en.jar"]] || How does a lens form an image? See how light rays are refracted by a lens. Watch how the image changes when you adjust the focal length of the lens, move the object, move the lens, or move the screen. ||


 * [|Electromagnetic Waves] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/Images/ejs_ehu_waves_emwave.jpg width="150" height="127" link="http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/waves_emwave.jar"]] || The Electromagnetic Wave model displays the electric field and magnetic field of an electromagnetic wave. The simulation allows an arbitrarily polarized wave to be created. The magnitude of the electric field components and the relative phase between the components of the electric field can all be changed via sliders. ||
 * [|Polarizer] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/Images/polarizer.jpg width="150" height="129" link="http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/optics_polarizer.jar"]] || The Polarizer program displays the effect of a plane polarizer on an incident electromagnetic wave. The polarization of the electromagnetic wave and the orientation of the polarizer can be modified. ||
 * [|Brewster's Angle] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/Images/ejs_ehu_waves_brewster.jpg width="150" height="127" link="http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/waves_brewster.jar"]] || The Brewster's Angle model displays the electric field of an electromagnetic wave incident on a change of index of refraction. The simulation allows an arbitrarily linearly (in parallel and perpendicular components) polarized wave to encounter the change of index of refraction. ||
 * [|Thick Lens] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/Images/ThickLens.gif width="150" height="80" link="http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/optics_ThickLens.jar"]] || The Thick Lens model allows the user to simulate a lens (mirror) by adjusting the physical properties of a transparent (reflecting) object and observing the object's effect on a beam of light. The user can adjust the concavity of the sides, the index of refraction and its environment, and the height and width of the object as well as the size of the incident light and the horizontal position of the transparent object. ||
 * [|Multiple Slit Diffraction] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/Images/multiple_slit.jpg width="150" height="49" link="http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/MultipleSlitDiffraction.jar"]] || The Multiple Slit Diffraction model allows the user to simulate Fraunhofer diffraction through single or multiple slits. The user can modify the number of slits, the slit width, the slit separation and the wavelength of the incident light. The scale of the diffraction pattern can also be changed and a plot of the light intensity can be toggled on and off with a checkbox. ||
 * [|Two-Color Multiple Slit Diffraction] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/Images/TwoColorMultipleSlit_icon.jpg width="150" height="83" link="http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/TwoColorMultipleSlitDiffraction.jar"]] || The Two-Color Multiple Slit Diffraction Model allows users to explore multiple slit diffraction by manipulating characteristics of the aperture and incident light to observe the resulting intensity. An exploration of resolving power in spectroscopy is included in the model. ||
 * [|Optical Resolution] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/Images/OpticalResolution.jpg width="150" height="150" link="http://www.cabrillo.edu/~jmccullough/Applets/OSP/Optics/optics_OpticalResolution.jar"]] || The Optical Resolution model computes the image from two point sources as seen through a circular aperture such as a telescope or a microscope. The simulation allows the user to vary the distance between the light sources and the diameter of the aperture, as well as the intensity of the light source. ||

The Java Applets were taken either from [|PhET] or [|Open Source Physics].
 * [|EM Wave] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/Flash/Optics/Images/EMWave.JPG width="300" height="200" link="http://www.cabrillo.edu/~jmccullough/Applets/Flash/Optics/EMWave.swf"]] || A 3 dimensional animation of the "far" fields of an oscillating charge. ||
 * [|Rotating Mirror and Reflected Wave] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/Flash/Optics/Images/RotatingMirror.JPG width="300" height="200" link="http://www.cabrillo.edu/~jmccullough/Applets/Flash/Optics/RotatingMirror.swf"]] || Illustrating that when a mirror is rotated by an angle, the reflected ray is rotated by twice that angle. ||
 * [|Reflection and Refraction] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/Flash/Optics/Images/ReflectionRefraction.JPG width="300" height="200" link="http://www.cabrillo.edu/~jmccullough/Applets/Flash/Optics/ReflectionRefraction.swf"]] || Illustrating reflection and refraction, including total internal reflection. ||
 * [|Refraction Explanation] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/Flash/Optics/Images/Refraction.JPG width="300" height="200" link="http://www.cabrillo.edu/~jmccullough/Applets/Flash/Optics/Refraction.swf"]] || This animation shows wave fronts entering a mediums at a non-zero angle of incidence. ||
 * [|Circular Polarization] || [[image:http://www.cabrillo.edu/~jmccullough/Applets/Flash/Optics/Images/CircPol.JPG width="300" height="200" link="http://www.cabrillo.edu/~jmccullough/Applets/Flash/Optics/CircPol.swf"]] || Circular polarization generated from a linearly polarized electromagnetic wave by a quarter-wave plate. ||

The Flash Animations were all taken from [|David M. Harrison] from the University of Toronto.