| Optics
> Polarization > Circular Polarization |
DCS#
6H30.30 |
BARBER POLE
DISPLAY
-
APPARATUS
cylinder
of
corn syrup
|
202-21-C
|
a
few grains of silver nitrate
|
202-21-C or Chem
|
slide
projector with circular mask
|
202-09-F
|
polarizing
filter in rotating mount with motor
|
101-02-D2
|
DC
power supply
|
202-08-D
|
mirror
|
101-06-E2
|
large
polarizer
|
202-21-C5
|
DESCRIPTION
Shine a beam of
polarized light through the cylinder. The sugar
solution is
optically active and rotates the plane of polarization through
an angle
that depends on the wavelength of the light and the depth of the
solution. The silver nitrate
scatters the light, producing a helix of color that rotates with
the
polarizer. It also inhibits the growth of bacteria.
The colors are more saturated if viewed through a second
polarizer because it eliminates some of the multiply scattered
light.
Insert a color filter or replace the white light with a laser,
and
maxima and minima can be seen.
REFERENCES