CD and Laser Pointer
CD and Laser Pointer
CD and Laser Pointer demo

 

Code Number: 6D20.32

Demo Title: CD or DVD Gratings

Condition: Excellent

Principle: Diffraction and Dispersion

Area of Study: Optics, Astronomy

Equipment: 

CD or DVD and Laser or Laser Pointer.

Procedure:

Shine the laser pointer on the CD at a very shallow angle, letting the reflection fall on the chalk board or onto a screen.  You should see at least 3 dots, which correspond to the 0th, 1st, and 2nd orders.

The etched CD without the metal coating can be used for some transmission diffraction grating type demo's.

References:

  • Santiago Velasco and Alejandro del Mazo, "Visualization of Four Optics Phenomena in a Single Experiment", TPT, Vol. 57, #6, Sept. 2019, p. 430.
  • Alan J. DeWeerd, "CD, DVD, and Blu-Ray Disc Diffraction with a Laser Ray Box", TPT, Vol. 54, #5, May 2016, p. 300.
  • Athanasios Velentzas, "Teaching Diffraction of Light and Electrons: Classroom Analogies to Classic Experiments", TPT, Vol. 52, #8, Nov. 2014, p. 493.
  • P. J. Ouseph, "CD Rainbows", TPT, Vol. 45, #1, Jan. 2007, p. 11.
  • James L. Hunt, "Five Quantitative Physics Experiments (Almost) Without Special Apparatus", TPT, Vol. 43, #7, Oct. 2005, p. 412.
  • Paul Gluck, "Compact Disk Optics", TPT, Vol. 40, #8, Nov. 2002, p. 468.
  • Tim Knauer, "A Compact Disk Transmission Spectroscope", TPT, Vol. 40, #8, Nov. 2002, p. 466.
  • "Cover Photo", TPT, Vol. 40, #8, Nov. 2002.
  • Scott R. Welty, "Long-Playing Diffraction Grating", TPT, Vol. 19, #3, Mar. 1981, p. 187, also A Potpourri of Physics Teaching Ideas - Optics and Waves, p. 231.
  • Rajeev Khare, "Use of a CD as a Dispersive Element in a Turntable Dye Laser", AJP, Vol. 73, #6, June 2005, p. 559.
  • James E. Kettler, "The Compact Disk as a Diffraction Grating", AJP, Vol. 59, #4, Apr. 1991, p. 367.
  • Wallace A. Hilton, "I-12", Experiments in Optical Physics, p. 39.
  • Martin C. Sagendorf, "Simple Spectroscope Using a Box and a CD", Physics Demonstration Apparatus, 2009. p. 88.
  • Bill Franklin, "The Compact Disc as a Diffraction Grating, Using a Laser", Teaching about Color & Color Vision, 1996, p. 3C-1.
  • Pat Murphy, Ellen Macaulay, and the Staff of the Exploratorium, "Reflections of a CD", Exploratopia, p. 313.
  • Jearl Walker, "6.108, Colors on Finely Grooved Items", The Flying Circus of Physics Ed. 2, p. 286.
  • Roman Ya. Kerzerashvili, "Abstract: Advanced Optics with Laser Pointer and Metersticks", 2005 Apparatus Competition, Salt Lake City, UT.
  • P. J. Ouseph, "Abstract: CD Rainbows", 2005 Apparatus Competition, Salt Lake City, UT.
  • "The Diffraction Grating", Selective Experiments in Physics, CENCO, 1962.
  • "Diffraction Grating, Simple", Selective Experiments in Physics, CENCO, 1959.
  • Curt Suplee, "Lasers and Compact Disks", Everyday Science Explained, National Geographic, p. 120 - 121.