Interference
PIRA classification 6D
Grayed Demos are either not available or haven't been built yet. |
6D10. Interference from Two Sources
PIRA # |
Demonstration Name |
Subsets |
Abstract |
6D10.05 |
interference model |
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6D10.10 |
double slit and laser |
pira200 |
Shine a laser beam through double slits of different widths and spacing. |
6D10.10 |
double slits and laser |
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Pass a laser beam through double slits of different widths and spacing. |
6D10.10 |
laser and double slit |
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Direct a laser through a double slits of different dimensions. |
6D10.10 |
double slit interference |
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Pass a laser beam through double slits on the Cornell slide. |
6D10.11 |
Cornel plate - two slit |
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6D10.14 |
making double slits |
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Photograph two dark wires against a white background with high contrast film and use the negative for a double slit. |
6D10.15 |
double slit on x-y recorder |
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Mount a photoresistor on the movable crossbar. |
6D10.15 |
double slit on X-Y recorder |
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Mount a detector on the the traveling arm of an X-Y recorder and trace out the intensity pattern of a double slit. |
6D10.17 |
double slit on photo diode array |
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6D10.17 |
photodiode array |
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Shine the diffraction pattern on a photodiode array and display the intensity plot on an oscilloscope. |
6D10.17 |
photodiode array detector |
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Project the pattern from the laser and adjustable slit onto a photodiode array and observe the intensity on an oscilloscope. |
6D10.20 |
microwave two slit interference |
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Microwave two slit interference. |
6D10.20 |
microwave double slit diffraction |
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The set up for double slit diffraction using 3.37 cm microwaves. |
6D10.20 |
microwave double slit |
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A 12 cm microwave double slit demonstration. |
6D10.20 |
microwave double slit interference |
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Two sets of slits with different spacing on the Brett Carrol microwave board. |
6D10.25 |
microwave double source interference |
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12 cm microwave is set up with two transmitters. |
6D10.30 |
two slit interference - hand held |
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Look at a filament lamp through parallel lines scratched in a dark plate. |
6D10.35 |
ripple tank incoherence |
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The necessary conditions for interference are shown with a dripping water double source that can be adjusted to show irregular changes in initial phase differences. |
6D10.36 |
coherence and interference |
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An interference pattern results from a laser grazing the wall of a glass tube. The effect is not observable with non coherent light. |
6D10.37 |
interference and coherence of light |
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More variance on the subject. |
6D10.37 |
coherence and interference in a tube |
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This explanation of the interference pattern from the inner and outer edges of a glass tube differs from AJP 40(3),470. |
6D10.38 |
cylindrical tube interference |
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The ring pattern from shining a point source down a reflecting cylindrical tube results from interference of two virtual sources. |
6D10.41 |
Fresnel biprism |
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A laser through a Fresnel biprism gives two interference sources. |
6D10.41 |
Fresnel biprism |
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A Fresnel Biprism is placed between a slit and projecting lens giving a pattern similar to a double slit. |
6D10.42 |
Billet half lens |
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A split convex lens acts like a Fresnel biprism and gives an interference pattern. |
6D10.46 |
double slit wavefront measurement |
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As the laser beam is scanned across the double slit, the interference pattern moves antiparallel to the laser beam translation. |
6D10.47 |
measuring interference fringes |
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Use two filaments. Line up the central image of one filament with the first maximum of the other filament. |
6D10.48 |
interference from "X" slits |
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Crossed slits produce hyperbolic interference patterns. |
6D10.51 |
computer generated interference |
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A simple GW-BASIC program for generating two point interference patterns. |
6D10.52 |
digital electronic diffraction |
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A digital electronic circuit acts like 16 slits, any of which can be open or closed, with either or both of two wavelengths. Discusses the various effects that can be shown with the apparatus. |
6D10.61 |
group and phase velocity by interfer |
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The reflected laser light from the glass/air interfaces of two glass slides of different thicknesses show group and phase velocity when the air gap between them is changed. |
6D10.90 |
3D interference patterns |
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Direct the laser interference pattern from the back of the room off a mirror and toward the students into a smoke filled box. |
6D15. Interference of Polarized Light
PIRA # |
Demonstration Name |
Subsets |
Abstract |
6D15.01 |
interference of polarized light |
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On using unpolarized light. |
6D15.10 |
interference of polarized light |
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Polarized laser light is focused by a lens on a small calcite crystal and the interference pattern of the two resulting beams depends on the type and orientation of a second polarizer. |
6D15.10 |
interference with polarized light |
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A polarized laser beam passes through a calcite crystal and a polarizing sheet is interposed and rotated to make fringes appear and disappear. |
6D15.14 |
interference question |
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Mellon AJP 30(10),772 was wrong and here is why... |
6D15.15 |
QM polarized light demos |
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Eigenstates of the prism, etc. |
6D15.20 |
polarized double-slit diffraction |
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The diffraction patterns from parallel and perpendicular light through a double slit. |
6D15.20 |
total interference |
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Show the standard interference patterns with Polaroids in each path aligned parallel, then rotate one and the pattern disappears. |
6D15.20 |
Fresnel-Arago law |
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Use a laser to obtain widely separated fringes from a double slit. Cut ribbons of polarizer and hold with orthogonal polarization in the two exit beams and the fringes disappear.. |
6D15.21 |
interference of polarized light |
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Pointer to articles in other publications. |
6D15.22 |
interference in polarized light |
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Demonstrating the Fresnel-Arago laws for interference in polarized light using a grating as a beam splitter and observing the interference fringes in its conjugate plane. |
6D15.25 |
interference with polarized light |
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Polarized light is passed through a double slit, the two output beams are polarized perpendicularly, and a third polarizer can be used as an analyzer. |
6D15.26 |
elliptically polarized interference |
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The double slit with orthogonal elliptical polarization. |
6D15.30 |
interference of polarized light |
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Put a quarter wave plate in one path of a Michelson interferometer and show the waves don't have to have the same polarization to interfere. |
6D20. Gratings
PIRA # |
Demonstration Name |
Subsets |
Abstract |
6D20.10 |
number of slits |
pira200 |
Shine a laser beam through various numbers of slits with the same spacing. |
6D20.10 |
Cornel plate - gratings |
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6D20.10 |
number of slits |
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A laser is directed through various numbers of slits with the same spacing. |
6D20.10 |
multiple slit interference |
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Pass a laser beam through three sets of multiple slits on the Cornell slide. |
6D20.11 |
project course grating |
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A course grating is placed between an illuminated slit and the projection lens. A fine grating must be placed near the screen. |
6D20.12 |
grating in air and water |
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Measure the pattern of a laser beam incident on a diffraction grating placed inside an empty aquarium and with it full of water. |
6D20.13 |
which side has the gratings? |
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Wet one surface of the grating with alcohol and if it is the grating side, the intensity of the diffraction maxima decrease. |
6D20.15 |
gratings and laser |
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6D20.20 |
projected spectra with grating |
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6D20.20 |
projected spectra with grating |
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White light, mercury, and sodium sources are passed through 300 and 600 lines per mm gratings. |
6D20.20 |
interference gratings |
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Shine a white light beam through gratings of 3000, 4000, and 6000 lines/cm. |
6D20.25 |
student gratings and carousel |
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see 7B10.10. |
6D20.26 |
measure wavelength with a grating |
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Look through a grating at a line source and measure the distance to the source and the angle of the lines. |
6D20.28 |
beer can spectroscope |
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Drink the beer, tape a replica grating over the hole, cut a slit in the bottom. |
6D20.28 |
film canister spectroscope |
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Make a slit in the cover of a film canister and place a grating over a hole in the bottom made with a #2 cork bore. |
6D20.30 |
grazing incidence diffraction |
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Grazing incidence on a very course grating produces minute path differences. |
6D20.31 |
measuring wavelength with a ruler |
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A laser is diffracted at grazing incidence off the rulings of a steel scale. |
6D20.31 |
measuring wavelength with a ruler |
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Diffraction of a laser beam by grazing incidence on a machinists rule. |
6D20.32 |
compact disk grating |
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Information on the pit and grove sizes and an example setup. |
6D20.35 |
wire diffraction gratings |
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Reconstruction of Fraunhofer's original gratings made of #42 wire at 80/inch. |
6D20.40 |
dispersion and resolving power |
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A discussion of the distinction between dispersion and resolving power of a grating. |
6D20.42 |
gratings and minimum deviation |
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On the advantages of using diffraction gratings at the angle of minimum deviation instead of the position of perpendicular incidence. |
6D20.45 |
first order gratings |
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Gratings that produce only one order either side of the central maximum are made by photographing Fraunhofer diffraction fringes. |
6D20.46 |
Babinet's principle - 2D |
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Carefully drawn black spots on white paper are photographically reduced and the positive and negative copies are used as complementary arrays. |
6D20.47 |
Babinet's principle |
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A technique for constructing complementary gratings for demonstrating Babinet's principle. |
6D20.50 |
crossed gratings and laser |
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Same as Ol-13. |
6D20.50 |
crossed gratings |
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Two gratings are crossed and placed in a laser beam. |
6D20.52 |
crossed gratings in smoke box |
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A laser and crossed gratings in a smoke box. Discusses patterns from skew beams. |
6D20.53 |
diffraction grating and laser |
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Show the beams coming out of the grating at angles by grazing the blackboard or using a cylindrical lens. |
6D20.55 |
two dimensional gratings and laser |
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6D20.55 |
two dimensional grating |
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View an automobile headlamp through a small square of silk. |
6D20.56 |
regular and irregular patterns |
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Use a computer to generate regular and irregular arrays of the same aperture and photo reduce them to make diffraction plates. |
6D20.56 |
hole gratings |
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A source for hole gratings of several spacings, sizes, and arrangements. |
6D20.57 |
optical crystal set |
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Seven sequences of four 2x2 slides used to in the simple Laue approach to diffraction by crystals. Winner of the 1973 AAPT apparatus competition. |
6D20.58 |
optical simulation of electron diffr |
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Generate and reduce dot patterns that generate patterns with laser light that are similar to various electron diffraction patterns. |
6D20.59 |
random multiple gratings |
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6D20.61 |
water droplets |
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Exhale on clean glass. |
6D20.62 |
red blood cells |
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Look through a drop of blood on a microscope slide at a point source or project onto a screen from a point source. |
6D20.63 |
dust on the mirror |
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Dust a bathroom mirror and hold a small light as close to the eye as possible. |
6D20.63 |
lycopodium powder diffraction |
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A collimated beam of white light is passed through a glass dusted with lycopodium powder giving a maximum at 50 cm with a 60' throw. |
6D20.64 |
scatter light interference |
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How to make a scatter plate with a speckle diameter of 3 microns. |
6D20.70 |
ultrasonic wave diffraction |
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Light is diffracted by ultrasonic waves in a liquid. |
6D20.75 |
speckle spots and random diffraction |
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The sparkling of a spot illuminated by a laser beam on the wall is caused by random interference patterns caused by scattered light. |
6D20.76 |
speckle patterns in arc light |
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Speckle patterns can also be seen in arc lamp light. The patterns disappear as the object is brought closer to the arc. |
6D20.76 |
speckle patterns in unfiltered sun |
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Speckle patterns from sunlight scattered by a diffusing surface are common. Train yourself to see them. |
6D20.80 |
reconstruction of diffraction patter |
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Reconstruct the image of a light source by viewing its diffraction pattern through a similar grating placed in front of the camera lens. |
6D20.85 |
Fabry-Perot "multiple slit" |
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An adjustable "multiple slit" interference pattern can be shown with a Fabry-Perot interferometer. |
6D30. Thin Films
PIRA # |
Demonstration Name |
Subsets |
Abstract |
6D30.10 |
Newton's rings |
pira200 |
Reflect white light off Newton's rings onto the wall. |
6D30.10 |
Newton's rings |
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Reflect light off a long focal length lens squeezed against a flat glass. |
6D30.10 |
Newton's rings |
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A long focal length lens is held against a flat. Note change of ring size with different colored light. |
6D30.10 |
Newton's rings |
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Newton's rings with monochromatic light. |
6D30.10 |
Newton's rings |
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Reflect white light off Newton's rings apparatus to a screen. |
6D30.11 |
Newton's rings - HeNe |
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Not the standard. The laser light reflected from the curved and flat surfaces of a plano-convex lens is superimposed on a screen. |
6D30.12 |
Netwon's rings - float glass |
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Some diagrams and pictures of arrangements using float glass (very flat) to demonstrate Newton's rings. |
6D30.20 |
soap film interference |
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Reflect white light off a soap film onto a screen. |
6D30.20 |
soap film interference |
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Project white light reflected off a soap film in a wire frame onto the wall. |
6D30.20 |
soap film interference |
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Reflect white light off a soap film onto a screen. |
6D30.20 |
soap film interference |
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Illuminate a soap film with an extended source in a darkened room. |
6D30.20 |
soap film interference |
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Project light reflecting off a soap film onto a screen. |
6D30.20 |
pira200 |
Reflect white light off a soap film on a wire frame. |
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6D30.21 |
stable black soap films |
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Vidal Sasson - Extra Gentle Formula makes black films lasting five minutes or longer. |
6D30.22 |
soap film transmission and reflectio |
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A configuration that allows simultaneous viewing of transmitted and reflected patterns shows the colors of corresponding bands are complementary. |
6D30.23 |
constant soap film |
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Fit a large graduate with a rectangular frame with the handle protruding through the stopper. Fill half full with soap solution. |
6D30.25 |
Boys rainbow cup |
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Rotate a hemispherical shell with a soap film across the front so the black spot forms in the middle. |
6D30.30 |
air wedge |
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A sodium lamp illuminates an air wedge between two plates of glass. |
6D30.30 |
air wedge with sodium light |
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Diffuse sodium light with frosted glass before reflecting it off two plane glass plates. |
6D30.30 |
air wedge |
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Reflect an extended monochromatic source off two large pieces of plate glass held together. |
6D30.30 |
glass plates in sodium light |
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The diffused light from a high intensity sodium lamp is viewed by reflection off one and two pieces of plate glass. |
6D30.40 |
Pohl's mica sheet |
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6D30.40 |
mica interference |
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Show interference by reflection of filtered mercury light from a mica sheet onto a screen. |
6D30.40 |
mica sheet |
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Reflect light from a mercury point source off a thin sheet of mica onto the opposite wall. Derivation. |
6D30.40 |
Pohl's mica thin film |
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Mercury light is reflected off a thin mica sheet. Mercury light source reference: AJP 19(4),248. |
6D30.40 |
Pohl's mica sheet |
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Mercury light reflects off a sheet of mica onto a screen. |
6D30.45 |
turpentine film |
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White light incident of the surface of turpentine on water at an angle of 45-60 degrees is focused on a screen. |
6D30.48 |
absorption phase shift |
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Cover the back of a microscope slide with streaks of an absorbing dye and observed under monochromatic light. |
6D30.50 |
temper colors |
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A thin film of oxide forms on a polished steel sheet when it is heated. |
6D30.60 |
interference filter |
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A interference filter for the mercury green line is used with white, mercury, and neon light at different angles of incidence. |
6D30.60 |
interference filters |
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White light is seen in reflection and transmission on a thread screen using three different interference filters. |
6D30.61 |
interference films |
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A broad source (36 sq in) He lamp is used to examine thin metal films. |
6D30.65 |
oil film |
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The thickness of a film of oil on a pan of water that can be varied by sliding an iron bar across the surface makes an excellent variable interference filter. |
6D30.70 |
microwave thin film interference |
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Sow interference by transmission and reflection with two ground glass sheets, one stationary and the other movable on an optical bench. |
6D40. Interferometers
PIRA # |
Demonstration Name |
Subsets |
Abstract |
6D40.10 |
Michelson interferometer |
pira200 |
Use a Michelson interferometer with either laser or white light. Count the number of fringes while turning the micrometer in one direction. |
6D40.10 |
Michelson interferometer |
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Pass laser light through a commercial interferometer onto the wall. Can also be done with white light. |
6D40.10 |
Michelson interferometer |
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Project colored fringes from white light onto a screen, insert a hot object in one path. |
6D40.10 |
Michelson interferometer -white ligh |
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A commercial interferometer with white light. Both circular and line fringes are shown. |
6D40.11 |
interferometer - large class |
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Use a laser with the Michelson interferometer and expand the exit beam with a microscope objective. |
6D40.12 |
Michelson interferometer - power |
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Measure the power of solar cells in the two outputs of the Michelson interferometer. |
6D40.13 |
Michelson interferometer alignment |
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Hints on alignment techniques. |
6D40.15 |
interference fringes with audio |
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A photocell detector detects fringes and the output is converted to an audio signal. |
6D40.16 |
Michelson - advanced topics |
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Use the Michelson interferometer to demonstrate graphically the Fourier transform nature of Fraunhoffer diffraction and introduce basic concepts of coherent optics. |
6D40.20 |
microwave interferometer |
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Thorough discussion of the microwave interferometer including using it to calibrate a meter stick. |
6D40.21 |
microwave interferometer |
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Three microwave interferometers: Lloyd's mirror, Michelson's interferometer, grid-detection interferometer, are shown. Pictures. |
6D40.22 |
microwave interferometer |
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Use 4 cm microwaves and 10" square platforms of plexiglass to demonstrate Lloyd's mirror, Michelson's interferometer, and grid-detection interferometers on the overhead. |
6D40.25 |
microwave interferometer |
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Demonstrate an interferometer using chicken wire mirrors and a 12 cm microwave. |
6D40.25 |
microwave Michelson interferometer |
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Make a microwave Michelson interferometer with window screen reflectors and a chicken wire half reflector. |
6D40.30 |
Jamin interferometer |
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The two mirrors are adjustable about mutually perpendicular axes. |
6D40.30 |
Jamin interferometer |
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Use second surface mirrors at and angle generate parallel beams in this interferometer. |
6D40.35 |
Sagnac interferometer - real fringes |
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Real fringes are observed with the Sagnac interferometer with both a point source and an extended source. Virtual fringes require an extended source. Also applies to Michelson interferometer. |
6D40.35 |
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Ealing Fabry-Perot interferometer setup. Applications: optical measurements, index of refraction of a gas, and the Zeeman effect. |
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6D40.40 |
triangular interferometer |
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The triangular interferometer is explained. Diagrams, Construction details in appendix, p. 1353. |
6D40.42 |
coupled cavity interferometer |
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A prism mounted on a phonograph turntable is used to rapidly vary the path length of the external cavity. |
6D40.45 |
coherence length |
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Use a long path interferometer to demonstrate the coherence length is at least 12 m. Also transverse coherence. |
6D40.45 |
long path interferometer |
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The movable mirror can be at least 6 m away giving a coherence length of 12 m. |
6D40.46 |
long path interferometer |
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A long path interferometer uses corner reflectors instead of mirrors and the output beam is directed onto a photodetector feeding an audio oscillator. |
6D40.47 |
double ended interferometer |
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Demonstrates the coherence of beams emitted from opposite ends of the laser tube. |
6D40.48 |
transverse coherence |
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Misaligning the mirrors still gives fringes. |
6D40.49 |
thick reflecting plate |
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Interference from waves reflected off two sides of a plate, limited to thin films in ordinary light, works in thick glass with lasers. |
6D40.50 |
Fresnel interferometers |
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Two different setups of Fresnel interferometers are discussed. |
6D40.54 |
Mylar Fabry- Perot interferometer |
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Design of an interferometer using metalized mylar as mirrors. |
6D40.54 |
inexpensive Fabry-Perot |
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Use standard "one-way" mirrors. |
6D40.54 |
low cost Fabry-Perot interferometer |
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Construction of Fabry-Perot devices from microscope cover glasses and plate glass. |
6D40.54 |
medium cost Fabry-Perot |
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Use Pyrex optical flats. |
6D40.54 |
low cost Fabry-Perot |
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Use surplus optically flat circular plates. |
6D40.54 |
low cost comment |
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Spacings up to 1/4" are possible. |
6D40.55 |
Fabry-Perot etalon |
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Directions for construction an inexpensive Fabry-Perot etalon. Reference: AJP 36(1),ix. |
6D40.56 |
Fabry-Perot interferometer |
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Add some mirrors to a commercially made linear positioning stage. |
6D40.57 |
simple gauge-length interferometer |
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A simple low-cost interferometer using only manufacturers' stock components. |
6D40.60 |
listening to doppler shift of light |
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Light from a laser beam is reflected off fixed and movable mirrors is mixed on a photodetector and the resulting signal is amplified and drives a speaker. |
6D40.60 |
satellite tracking using doppler |
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Beats between a generator and Sputnik I are recorded and played back while projecting a spot on a map indicating position. |
6D40.60 |
spherical mirror interferometer |
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An interferometer with two spherical mirrors is designed to show wind around objects, heat effects, and strain effects. |
6D40.61 |
optical doppler shift |
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Show the frequency shift of a laser beam bouncing off a moving mirror with a spectrum analyzer. |
6D40.61 |
doppler effect with light |
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Using a laser beam, retroreflector on a moving air track, beam splitter, and stationary mirror, observe the signal of the beat pattern from a silicon photodiode on an oscilloscope. |
6D40.62 |
doppler radar |
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Diagram of apparatus for Doppler radar. The reflector is mounted on a 1/32 scale slot car. |
6D40.62 |
doppler shift with microwaves |
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Some of the transmitted signal and the signal received after reflection off a moving object are fed to a mixer. |
6D40.70 |
complicated doppler shift setups |
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Sophisticated Doppler shift experiments with construction details, diagrams, and 7 references. |