6D20.15 - Gratings - Wavelength of a Laser

Code Number:
6D20.15
Demo Title:
Gratings - Wavelength of a Laser
Condition:
Excellent
Principle:
Diffraction and Wavelength
Area of Study:
Optics, Astronomy
Equipment:
Different color lasers, slit plate, meter stick or meter tape measurer.
Procedure:

The laser array of 6 different colors can be found at: 7G55.10.

Some simple geometry will allow you to determine the wavelength of the laser light you shine through a single slit.  You will need to know the width of the slit, the distance from the slit to the screen, and the spacing between the spots that make up the interference pattern.  Use lasers of different colors if desired.

References:
  • Dinh Xuan Khoa and Nguyen Huy Bang, "A Low-Cost Experimental Kit for Teaching Wave Optics Based on the CDIO Approach", TPT, Vol. 57, #3, Mar. 2019, p. 168.
  • David K. Walker, "Visible Diffracted Rays", TPT, Vol. 11, #7, Oct. 1973, p. 435, reprinted in TPT, Vol. 40, #3, Mar. 2002, p. 185.
  • Borislaw Bilash II and David Maiullo, "Bragging About Diffraction", A Demo a Day: A Year of Physics Demonstrations, p. 352.

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.