Diffraction - Laser and Adjustable Slit



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 Code Number :   6C10.15  

Disclaimer:

Reprinted by permission of Dick Berg, University of Maryland, for use on this website.

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Condition :   Good  
Principle :   Diffraction of Waves  
Area of Study :  Optics, Astronomy   
Equipment :   Helium-neon laser (2 to 5 mw.), Optics bench, Single Slit (Adjustable).  

Procedure :   Put the adjustable slit in the path of the laser beam. As you adjust the slit width observe the changing diffraction patterns. 

Another variation of the previous single slit demo is to partially submerge the variable slit in a tank of water. Measurable differences between the pattern produced through the air as opposed to through the water can be observed and used for calculations.  

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   References

Samuel Hirchman, Eugene Hecht, "What Happens if w < l?", TPT, Vol. 19, # 6, Sept. 1981, p. 427.

Mario Iona, "Comments About Slit Diffraction", TPT, Vol. 10, # 6, Sept. 1972, p. 323.

 

Ol-7:  Freier and Anderson,  A Demonstration Handbook for Physics.

 

O-505:  "Fixed, Variable & Finger Slit,"  DICK and RAE Physics Demo Notebook.

 

Robert Ehrlich,  "Variable-Width Slit Using Razor Blades,"  Turning the World Inside Out, p. 202- 203.

"Diffraction," Exploratorium Science Snackbook, p. 38.1 - 38.2.



Mail Questions and Comments to:  Dale Stille