Diffraction
PIRA classification ##
Grayed Demos are either not available or haven't been built yet. |
6C10. Diffraction Through One Slit
PIRA # |
Demonstration Name |
Subsets |
Abstract |
6C10.10 |
single slit and laser |
pira200 |
Shine a laser beam through single slits of various sizes. |
6C10.10 |
single slit and laser |
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A laser beam is passed through slits of various widths are shown on the wall. |
6C10.10 |
single slit and laser |
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Direct laser beam through single slits of various sizes. |
6C10.10 |
single slit diffraction |
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Diffraction pattern from a laser passing through an adjustable slit spreads as the slit is closed |
6C10.12 |
Cornell plate - single slit |
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6C10.12 |
Cornel plate - single slit |
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6C10.12 |
single slit diffraction (Cornell) |
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Laser and Cornell slide - measurements from on screen can be used in calculations. |
6C10.15 |
adjustable slit and laser |
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Shine a laser beam through an adjustable slit. |
6C10.15 |
adjustable slit and laser |
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6C10.15 |
laser and adjustable slit |
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Project a laser beam through an adjustable slit. |
6C10.15 |
diffraction limited resolution |
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A beam of light is projected through an adjustable slit into a telescope attached to a TV camera. The central slit widens as the slit is closed. |
6C10.20 |
two finger slit |
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6C10.20 |
two finger slit |
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Have each student look at a vertical filament lamp through the slit formed by holding two fingers together. |
6C10.21 |
adjustable single slit |
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Look through a vernier caliper toward a monochromatic light 5 to 10 m away. |
6C10.25 |
single slit diffraction - hand held |
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Look at a filament through a dark plate with a line scratched in it. |
6C10.26 |
single and double slits |
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Single and double lines are ruled on a photographic plate. Students look at a line filament covered with half red and half blue filters. A ruling tool is described. |
6C10.27 |
Cornell plate |
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Pass out Cornell plates to the students and have them look at a line filament. |
6C10.27 |
Cornell plate |
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Pass out the Cornell plate. |
6C10.30 |
slit on photodiode array |
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6C10.30 |
slit array |
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A slit array of randomly spaced single or double slits follows the imaging lens projecting a slit on the wall. |
6C10.30 |
single and double slit projected |
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Focus a slit on the wall and place photographic plates with slits near the lens. For the single slit, parallel lines are unevenly spaced. For the parallel slit, pairs of lines of equal spacing are randomly spaced. |
6C10.33 |
white light diffraction |
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A slit is projected on the wall and a second slit is placed at the focal point of the lens. |
6C10.43 |
rotating mirror detector |
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A rotating mirror sweeps the interference pattern across a photodiode and the output is displayed on an oscilloscope. |
6C10.43 |
electric razor detector sweep |
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A mirror mounted on an electric razor is used to sweep a diffraction pattern across a sensitive photodiode, and the resulting pattern is displayed on an oscilloscope. |
6C10.43 |
motorized slit sweep |
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A slit is motorized and a microscope objective projects the observation plane onto a photodiode detector. The scope sweep is synchronized with the motor speed. |
6C10.43 |
rotating mirror detector |
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A rotating mirror sweeps a diffraction pattern across a photodiode and the pattern is shown on an oscilloscope. |
6C10.44 |
single slit and relative phase |
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A double slit is used to sample the light from a single slit to give information about the relative phases. |
6C10.47 |
tv tube detector |
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Look at the composite output from a TV camera on an oscilloscope at the same time the pattern is displayed on the screen. |
6C10.50 |
microwave diffraction |
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6C10.50 |
microwave diffraction |
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3 cm microwave and a single slit. |
6C10.50 |
microwave single slit diffraction |
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Single slit diffraction with microwave apparatus. |
6C10.50 |
microwave diffraction |
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An adjustable slit on the Brett Carrol microwave board (receiver and transmitter are mounted on a large vertical circle with a built in LED bar graph signal strength indicator. |
6C10.61 |
diffraction limited resolution |
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Demonstrating the resolving power of a microscope is tricky. |
6C10.62 |
diffraction limited resolution |
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A "picket fence lantern slide with an adjustable slit on the screen side of the projection lens. |
6C10.64 |
microscope resolving power |
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Modify ordinary objectives by inserting diaphragms at the back focal plane. Use a binocular microscope with a normal ocular on one side. |
6C20. Diffraction Around Objects
PIRA # |
Demonstration Name |
Subsets |
Abstract |
6C20.10 |
Arago's (Poisson's) spot |
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Shine a laser beam at a small ball and look at the diffraction pattern. |
6C20.10 |
laser and diffraction objects |
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A laser beam is diffracted around balls. |
6C20.10 |
Arago white spot |
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A corridor demonstration of using a flashlight bulb, a ball bearing and a small telescope. |
6C20.10 |
diffraction about a circular object |
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A coin is placed between a pinhole and a screen. A small hole is punched in the screen in the shadow of the coin. While looking at the coin through the hole, a ring of light will be seen. |
6C20.10 |
Arago's spot |
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Arago's spot with a small lamp, telescope, and ball bearing over a 90' distance. |
6C20.10 |
Poisson's bright spot |
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A point source is used to illuminate a small ball. |
6C20.12 |
photographing diffraction |
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Simple setup of a camera with the lens removed, an object and a flashlight bulb. |
6C20.13 |
large scale diffraction |
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Use a penny and a long light path. |
6C20.13 |
diffraction around a coin |
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Project the shadow from a point source onto a translucent screen. |
6C20.15 |
knife edge diffraction |
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6C20.15 |
diffraction around objects |
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Diffraction of laser light around a razor edge, wires, small balls, etc. is viewed on a screen. |
6C20.15 |
knife edge diffraction |
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Slowly move a knife edge into a laser beam. |
6C20.16 |
laser diffraction objects |
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A list of recommended diffraction objects for use with laser beams. Pictures. |
6C20.17 |
diffraction around large objects |
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Expand a laser beam to 1-3" and look at the diffraction pattern of large objects. A folded optical path brings the viewing screen close to the object. |
6C20.18 |
Fresnel diffraction |
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Objects placed between a pinhole and a screen show striking diffraction patterns. |
6C20.20 |
thin wire diffraction |
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6C20.20 |
diffraciton pattern of a hair |
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Put a hair in a laser beam. |
6C20.20 |
fake double slit |
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Put a straight pin in the laser beam. |
6C20.20 |
diameter of a hair by diffraction |
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Use Babinet's principle to measure the diameter of a hair by the fringes. |
6C20.20 |
thin wire diffraction |
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Place a .22 mm dia wire in a laser beam and measure the diameter by the diffraction pattern. Measurements can be taken from the video. |
6C20.22 |
shadow of a needle |
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A point source is placed behind a pair of needles. |
6C20.30 |
pinhole diffraction |
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6C20.30 |
Airy diffraction rings |
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As a laser beam is stopped down to a region of constant intensity, the Airy diffraction rings will appear. |
6C20.30 |
pin hole diffraction |
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A laser passes through a pinhole in aluminum foil. Data can be taken from the video. |
6C20.33 |
triangular aperature |
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The Fraunhofer diffraction pattern of a triangular aperture is predicted by an argument very similar to that used for a single slit. |
6C20.40 |
zone plate lens |
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Use a photographic zone plate lens with an expanded laser beam. |
6C20.42 |
zone plates on a laser printer |
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A program to produce zone plates on a laser printer with discussion of limitations and applications. |
6C20.45 |
microwave Fresnel zones |
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A aluminum sheet with concentric rings that can be removed and replaced in various configurations is sized to work with a microwave transmitter. |
6C20.45 |
microwave Fresnel diffraction |
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Circular apertures are cut in aluminum sheets to simulate zone plates. |
6C20.45 |
microwave Fresnel zones |
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A 12 cm microwave Fresnel zone demonstration. |
6C20.46 |
microwave zone plates |
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The design of three varieties of microwave zone plates for 12 cm waves and lecture room use. |
6C20.51 |
pass the razor blade |
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Students hold a razor blade close to the eye so as to cut off part of an arc lamp. |
6C20.52 |
diffraction peep show |
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A 5 m long box holds a permanent diffraction setup. |
6C20.58 |
parallel beam array |
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An array of 25 small holes is projected to give parallel light beams which are used with slits and apertures to give patterns on the wall. |
6C20.62 |
diffraction by a feather |
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An image of a slit is blocked by a vertical rod. When a feather is placed between the lens and slit, light is scattered by diffraction onto the screen. |
6C20.91 |
viewing diffraction on TV |
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If the laser beam is expanded, diffraction patterns can be projected directly onto the bare videcon tube. |