6H30.40 Circular Polarization



This demonstration presents an example of optical activity. Because of its molecular shape, corn syrup is optically active. Saturated negative or subtractive, colors will be produced if the corn syrup is placed between the 2 polarizing disks. (The Video Encyclopedia of Physics Demonstrations)


  • Corn Syrup
  • 2 polarizing filters
  • Small beaker with flat bottom
  • 5 small rods
  • 2 rod stands
  • 5 S clamps
  • 1 Clamp
  • 2 ring stands
  • Mounted laser pointer
  • Mirror

Setup Procedure:

  1. Place the 2 rod stands next to each other
  2. Attach the mounted laser to an S clamp and place it on the bottom of a stand
  3. Attach an S clamp to the same stand as the laser at the top
  4. Attach the mirror and small rod to another S clamp, and attach that to the top S clamp on the stand
  5. On the other stand attach an S clamp to the bottom with a ring stand on it.
  6. Above the S clamp with a ring stand attach another S clamp with the clamp and beaker in the clamp
  7. At the top of the rod stand attach another ring stand to an S clamp
  8. Put the 2 polarizing filters atop the ring stands

Demonstration Procedure:

  1. Turn the laser on
  2. Turn one of the polarizing filters so that you see the laser beam disappear
  3. Add corn syrup to the beaker slowly to see the polarization reverse
  4. When finished, turn off the laser

Laser Light Laser Light
Do not stare at the laser beam. Do not point the laser at students