6D20.50 - Diffraction - Crossed Screens & EPROMS

Code Number:
Demo Title:
Diffraction - Crossed Screens & EPROMS
Two-Dimensional Gratings
Area of Study:
Optics, Astronomy
Helium-Neon Laser (2 to 5 mW), Optics Bench, Meter Stick, Plastic Ruler (Clear) with cm Marks, Tape Measure (25 ft.), Mesh Screens (3, Standard U.S.), Laser Pointer, and Slides Folders Containing a Very Fine Mesh Screen.

Two dimensional diffraction can be shown with the mesh screens.  Just put them into the path of the laser beam and observe the patterns.

The holographic "rainbow" glasses that are used to view fireworks are essentially crossed diffraction grating.  Place the lens of the glasses into the path of a laser beam and observe the diffraction pattern.

The slides contain a very fine mesh screen.  The screen is fine enough that it shows not only a two dimensional diffraction pattern, but also an interference beat pattern.

An EPROM chip will also give a two dimensional diffraction pattern which can be relected onto a nearby screen.

  • Kristin Rabosky, Colin Inglefield, Kiley Spirito, "Interference and Diffraction in Modern Technology: A New Approach for an Introductory Physics Laboratory Experiment", TPT, Vol. 58, #9, Dec. 2020, p. 646.
  • Fabrizio Logiurato, Luigi Gratton, and Stefano Oss, "Optical Simulation of Laue Crystal Diffraction with New Experiments on Diffraction", TPT, Vol. 58, #2, Feb. 2020, p. 130.
  • Ravi Kant Avvari, "Two-Dimenional Diffraction Pattern by a Silk Cloth", TPT, Vol. 58, #1, Jan. 2020, p. 46.
  • Jennifer J. Birriel, "Diffraction by 'Sheer Coincidence'", TPT, Vol. 56, #9, Dec. 2018, p. 648.
  • Tom Ekkens, "Two-Dimensional Light Diffraction From an EPROM Chip", TPT, Vol. 56, #2, Feb 2018, p. 70.
  • D. Rae Carpenter Jr. and Richard B. Minnix, "S-225. Scarf and Hosiery", DICK and RAE Physics Demo Notebook, 1993.
  • D. Rae Carpenter Jr. and Richard B. Minnix, "O-515. Wire & Photo Mesh with Laser", DICK and RAE Physics Demo Notebook, 1993.
  • G. D. Freier and F. J. Anderson, "Ol-13", A Demonstration Handbook for Physics.
  • G. D. Freier and F. J. Anderson, "Ol-10", A Demonstration Handbook for Physics.
  • Jearl Walker, "6.104. Lights Through a Screen, Lines Between Fingers", The Flying Circus of Physics Ed. 2, p. 283.
  • Gordon McComb, "Laser, Ray Guns, & Light Cannons", p. 124.
  • Brian Jones and Matt Fackelman,  "Diffraction Screen- The Other Light Phenomenon",  Don't Forget the Duct Tape! - The How and Why of the Experiments of the Little Shop of Physics - A Work in Progress, p. 37.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.