Demonstrations

Interference - Air and Water (Db. Slit)

Code Number :	6D10.12
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 of Waves
Area of Study :	Optics, Astronomy
Equipment :	Laser with diffusing lens, Cornell plate (db. slit)., refraction trough, lab jacks, screen.
Procedure :	Set up the equipment as shown with the double slit and beam at the lens end of the refraction trough. Several adjustments have to be made with the tank and the laser so that the two patterns fall one on top of the other. Due to the index of refraction of the water this probably means that the laser and the tank will not be exactly level. When properly adjusted a 3 bar pattern in the air should have a 4 bar pattern under it through the water.

References

Brian Houser, "Demonstrating the Decreased Wavelength of Light in Water," TPT, Vol. 39, # 4, p. 228, (April 2001).

P.J. Ouseph, "Refraction of Diffracted Light," TPT, Vol. 36, # 7, p. 420, (Oct. 1998).

G.R. Davies, "Interference and Diffraction Corridor Demonstrations," TPT, Vol. 33, # 4, p. 244, (April 1995).

Simon George and Robert Doebler, "Index of Refraction Using a Diffraction Pattern in a Fishtank," TPT, Vol. 29, # 7, p. 462, (October 1991).

Douglas C. Jenkins, Frank A. Smith, Jr., "Lecture Hall Demonstrations Or Fundamental Optics Made Obvious", TPT, Vol. 18, # 1, Jan 1980, p. back cover.

A. T. Mogill, "Velocity, Wavelength and Frequency Relations for Light", TPT, Vol. 13, # 9, Dec 1975, p. 555.

Richard F. Kotheimer, "Fish Tank" Laser Diffraction", TPT, Vol. 12, # 5, May 1974, p. 307.

Shyam Singh, "Diffraction Method Measures Refractive Indices of Liquids", Physics Education, Vol. 39, (3), 2004, p. 273.

Mail Questions and Comments to: Dale Stille