6D30.46 - Thin Film Interference - Alcohol Film

See paragraph one in the procedure section.
Code Number:
Demo Title:
Thin Film Interference - Alcohol Film
Thin Film Interference
Area of Study:
Laser with expanding lens, front surface mirror, isopropyl alcohol, paper towel or cotton swab.

Expand the beam of the laser and reflect it off a front surface mirror onto a screen.  Dab or spray some isopropyl alcohol onto the mirror.  As the alcohol evaporates, interesting and moving interference patterns are observed.

  • Arthur Eisenkraft, "Interference Patterns Produced an Evaporating Film", TPT, Vol. 17, # 6, Sept. 1979, p. 392.
  • Gordon McComb,  Lasers, Ray Guns, & Light Cannons - Projects from the Wizard's Workbench, p. 153.

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