Demonstrations

Diffraction Around Objects - Poisson's Spot

Code Number :	6C20.10
Disclaimer:	Reprinted by permission of Dick Berg, University of Maryland, for use on this website. The demonstrations contained and referenced herein are listed for the purposes of cataloging and describing physics demonstrations which should be conducted only under the direction of a trained instructional support professional or physicist. These demonstrations are not presented for the purpose of being conducted by persons unconnected to this Facility and/or persons not consulting with or being supervised by the recognized instructional support professional or physicist and his/her staff. The University is responsible only for those demonstrations carried out using its own equipment using established safety and scheduling policies, and bears no responsibility for those choosing to use this source material for their own purposes. All demonstrations described and contained herein are public domain, and can also be found in reference materials in libraries, bookstores, and electronic sources. Further information regarding legal liability in use of demonstrations and labs will be found on the web site Injuries in School/College Laboratories in USA. The University of Iowa Disclaimers: University of Iowa Disclaimer All Rights Reserved..
Condition :	Good
Principle :	Diffraction Patterns & Fresnel Diffraction, Edge Diffraction
Area of Study :	Optics
Equipment :	Optics Table, Laser (2 to 5 mw.), Beam Expander, Small Paper Screen and Holder, Ball Bearings mounted on Glass, Razor Blade, Video Camera.
Procedure :	Place the beam expander onto the laser. Place the razor blade or the ball bearings into the path of the laser beam and direct this onto the small screen . Viewing the diffraction patterns around the object with the video camera can be done by focusing the camera onto the back side of the screen. In some cases it will work much better if instead of using the small screen and the video camera, you dispense with these and direct the diffraction pattern onto the screen at the other end of the lecture room.

References

Michael E. Harrison, C. Thomas Marek, and James D. White, "Rediscovering Poisson's Spot," TPT, Vol. 35, # 1, p. 18-19, (Jan. 1997).

Jack Higbie, "More on Poisson's Spot", TPT, Vol. 35, # 4, Apr. 1997, p. 197.

Ronald D. Wong, "Still More on Poisson's Spot", TPT, Vol. 35, # 4, Apr. 1997, p. 197.

Gordon R. Gore, "Diffraction Photographs with a Laser Pointer", TPT, Vol. 32, # 3, March 1994, p. 174.

Robert a. Barttett, "Poisson's Circles?", TPT, Vol. 32, # 6, Sept. 1994, p. 326.

Andrew DePino Jr. "Unusual Diffraction Patterns." TPT, Vol. 25, # 4, p. 219, (April 1987).

John B. Johnston, "Projecting Poisson's Spot", TPT, Vol. 16, # 3, Mar. 1978, p. 179.

R. C. Nicklin and J. Dinkins, "Laser Diffraction Photography", TPT, Vol. 12, # 5, May 1974, p. 295.

John Dowling, Jr., and John Swanson, "A Short Note on "The Poisson Distribution" Lab", TPT, Vol. 11, # 9, Dec. 1973, p. 543.

Mimi S. Lafleur and Peter F. Hinrichsen, "An Experimental Approach to Teaching Statistics", TPT, Vol. 10, # 6, Sept. 1972, p. 314.

James Moore, "Viewing Diffraction Fringes", TPT, Vol. 9, # 3, March 1971, p. 153.

Andrzej Kolodziejczyk, Zbigniew Jaroszewicz, Rodrigo Henao and Orlando Quintero, "An Experimental Apparatus for White Light Imaging by Means of a Spherical Obstacle", AJP, Vol. 70, # 2, Feb. 2002, p. 169.

O-530: "Needle, Slit, and Razor Blade," DICK and RAE Physics Demo Notebook.

O-555: "Poisson's Spot," DICK and RAE Physics Demo Notebook.

O-7f: Wallace A. Hilton, Physics Demonstration Experiments.

L-78: Richard Manliffe Sutton, Demonstration Experiments in Physics.

Jearl Walker, "A Ball Bearing Aids in the Study of Light and Also Serves As a Lens," The Amateur Scientist, (November, 1984).

Richard E. Berg, "DEMO HINTS: Laser Diffraction", PIRA Newsletter, Vol. 3, # 11, March 31, 1989, p. 3.

5.98: Jearl Walker, "Poisson Spot," The Flying Circus of Physics with Answers.

C. Harvey Palmer, "Experiment B13: Demonstration of Fresnel Diffraction by Circular Apertures and Obstructions," Optics - Experiments and Demonstrations, John Hopkins Press, 1962.

"Diffraction Grating, Simple", Selective Experiments in Physics, CENCO, 1962.

Mail Questions and Comments to: Dale Stille