We're sorry but this page doesn't work properly without JavaScript enabled. Please enable it to continue.
Feedback

Optics: Polarization of Light and Polarization Manipulation

00:00

Formal Metadata

Title
Optics: Polarization of Light and Polarization Manipulation
Subtitle
Scattered light in a dielectric
Title of Series
Number of Parts
49
Author
License
CC Attribution - NonCommercial - ShareAlike 4.0 International:
You are free to use, adapt and copy, distribute and transmit the work or content in adapted or unchanged form for any legal and non-commercial purpose as long as the work is attributed to the author in the manner specified by the author or licensor and the work or content is shared also in adapted form only under the conditions of this
Identifiers
Publisher
Release Date
Language

Content Metadata

Subject Area
Genre
Abstract
This resource contains demonstrations used to illustrate the theory and applications of lasers and optics. A detailed listing of the topics can be found below. Lasers today are being used in an ever-increasing number of applications. In fact, there is hardly a field that has not been touched by the laser. Lasers are playing key roles in the home, office, hospital, factory, outdoors, and theater, as well as in the laboratory. To learn about lasers and related optics, one usually takes a course or two, or acquires the necessary information from books and journal articles. To make this learning more vivid and more exciting, and, one hopes, more understandable, one needs to see some of the basic phenomena involved. To fill this need, Professor Ezekiel has videotaped 48 demonstrations that illustrate most of the fundamental phenomena relating to lasers and physical optics. By using split-screen inserts and a wide range of video-recording capabilities, it is possible to show real-time effects in lasers and optics with the simultaneous manipulation of the components that cause these effects. In this way, one can see effects in close up that would be difficult, if not impossible, to display in front of an audience or in the classroom. These video demonstrations are designed for: The individual student of lasers and optics who wants to observe the various phenomena covered in theoretical treatments in courses, books, and technical papers. The Instructor in lasers and optics in a company, university, college, or high school who wants to illustrate, in class, many of the fundamental phenomena in optics and lasers.
LaserVideoOpticsPolarization (waves)LightGround stationMaterialQuality (business)
LaserNeon lampLightPlane (tool)DielectricLecture/Conference
Avro Canada CF-105 ArrowPlane (tool)Transmission (mechanics)LightPolarization (waves)Control rodPlatingWind waveRear-view mirrorGlassArbeitszylinderDielectricGaussian beamLaserCartridge (firearms)
Casting defectReflexionskoeffizientLightAngle of attackArbeitszylinderDisplay devicePolarization (waves)Direct currentWoodturningControl rodRayleigh scatteringMaterialLaserTurningGruppensteuerungBestrahlungsstärkeLinearpolarisationPhase (matter)FACTS (newspaper)Plane (tool)
FACTS (newspaper)Plane (tool)LightEffects unitControl rodPolarization (waves)Transmission (mechanics)Cartridge (firearms)Avro Canada CF-105 ArrowScatteringSpare partScreen printingWatchComputer animation
DielectricLightMeeting/Interview
Polarization (waves)Plane (tool)LightGaussian beamScatteringControl rodLecture/ConferenceMeeting/Interview
Transcript: English(auto-generated)
The following content is provided under a Creative Commons license. Your support will help MIT OpenCourseWare continue to offer high quality educational resources for free. To make a donation or view additional materials from hundreds of MIT courses, visit MIT OpenCourseWare at ocw.mit.edu.
In this demonstration, I'm going to illustrate one or two interesting properties relating to the propagation of light in a dielectric. The setup is very simple. Here we have a plane polarized laser, helium neon laser.
Here's the beam from the laser. We reflect it by this mirror into a quarter wave plate. Now over here, the light is circularly polarized. Then we pass the circularly polarized light through a polarizer over here so that as we rotate
the transmission axis of the polarizer, we can generate linearly polarized light over here with different planes of polarization. For example, when the arrow or the transmission axis of the polarizer is horizontal,
we have horizontally polarized light, plane polarized light. And when the arrow is vertical, for example, we have plane polarized light in the vertical plane. So this polarized light enters this dielectric cylinder here.
Normally, one would use a piece of glass. But in this case, I'm using a piece of lucite because I have a piece of lucite available. And then the light then, after passing through the lucite cylinder, goes off onto the wall.
So now what I'm going to do is change the polarization of light and look at the light scattered from the rod. First of all, if we take a close look at the rod,
we can see, in fact, we can see very little. We can see a hot spot over here. That's the reflection at this boundary, Fresnel reflection. And we also see a hot spot over here, which is the reflection at the exit face of the rod. We don't see any beams of light leaving the cylinder
at any other angle. However, what we do see, and I hope you can see it, is a faint streak marking the direction of the laser beam in the rod.
This is due to Rayleigh scattering in the material. Now, let's look at the polarization of the Rayleigh scattered light in the material. Now, in the insert, you see that the polarization of the light is vertical, and the camera
is looking in a horizontal direction at the scattered light. Here you see that you make out there is some red light. Now, when I go to horizontal polarization, you see that the scattered light is extinguished.
When I go back to the vertical polarization, linearly polarized light in the vertical plane, you see that the light comes back, and you can see it. But I know that this is not a great display. So what we'll do now, we'll turn down the lights
so we can see the effect much better. Now that the room lights are dimmed, we can see the effect much better in the lower part of the screen. In the upper right-hand corner, you see the polarizer being rotated,
or the transmission of the axis of the polarizer being rotated, so that we can select any plane of polarization we want. In this case, with a vertical arrow, we have vertically polarized light going into the lucite rod.
Then you see that the scattered light is pretty bright. Now, watch carefully. As I rotate the plane of polarization of the light, of the incident light, you can see that the scattered light is getting extinguished. In fact, when I have plane polarized light
in the horizontal plane, I see very little scattered light. Let's do it again. Let's go back to plane polarized light in the vertical plane. You see a lot of scattered light. And where the horizontal plane, when incident light is
polarized in the horizontal plane, you see very little scattered light. Remember, the camera is looking from the side of the lucite tube. In summary, we've seen one or two interesting properties relating to the propagation of light in a dielectric material, like a piece of lucite.
We saw that the scattered light from the beam within the rod varies with the incident polarization. And we're leaving it to you to explain that when the incident polarization is plane
polarized in the vertical plane, we saw a lot of scattered light when we looked from the side. And when the incident polarization was plane polarized in the horizontal plane, we saw almost no light at all scattered from the beam within the rod. So this is left to you to explain.