Zone Plate Demos
Blank CD Zone Plates

 

Code Number: 6C20.40

Demo Title: Zone Plates

Condition: Good

Principle: Focusing by Plates and Lines

Area of Study: Optics

Equipment:

Zone Plates (In Optics Table), Laser (2 to 5 mw.), Beam Expander lens, White Paper Screens, Object for imaging (Razor Blade), Green Laser Pointer.

Procedure:

Put the beam expander on the laser and direct this expanded beam onto one of the zone plates. Observe the focusing properties and characteristics.  NOTE:  Using a camera with an adjustable iris is required. When using a camera to show this to a larger classroom the spacing will be critical.  The spacing should be as in the first picture as this will allow the focus spot to be observed well without oversaturating the camera.  If you are viewing this in a small classroom where the students view this directly, you can use a much shorter spacing between the laser, plate, and screen.  

A CD or DVD without the silvered coating may be used as a zone plate.  Use an overhead projector or a slide projector as a light source and hold the CD or DVD near a screen to see the focusing effect.

References:

  • Paul Gluck, "Compact Disk Optics", TPT, Vol. 40, #8, Nov. 2002, p. 468.
  • Vicente Moreno, Juan Felix Roman, and Jose Ramon Salgueiro, "High Efficiency Diffractive Lenses: Deduction of Kinoform Profile", AJP, Vol. 65, #6, June 1997, p. 556.
  • Charles W. Clark and Yurii N. Demkov, "Making Zone Plates with a Laser Printer", AJP, Vol. 59, #2, Feb. 1991, p. 158.
  • H. Malcolm Childers and David E. Stone, "Solution to the Fresnel Zone Plate Problem", AJP, Vol. 37, #7, July 1969, p. 721.
  • Milton Sussman, "Elementary Diffraction Theory of Zone Plates", AJP, Vol. 28, #4, Apirl 1960, p. 394.
  • Albert V. Baez, "Focusing by Diffraction", AJP, Vol. 20, #5, May 1952, p. 311.
  • Ora E. Myers, Jr. "Studies of Transmission Zone Plates", AJP, Vol. 19, #6, Sep. 1951, p. 359.
  • Ol-23:  Freier and Anderson, A Demonstration Handbook for Physics.
  • Wallace A. Hilton, "I-15", Experiments in Optical Physics, p. 41.
  • T. Kallard, "Optical Method for Producing Zone Plates", Exploring Laser Light, p. 234.
  • C. Harvey Palmer, "Experiment B13: Demonstration of Fresnel Diffraction by Circular Apertures and Obstructions",  Optics - Experiments and Demonstrations, John Hopkins Press, 1962.