Optics >
Polarization > Polarization by Double Refraction
DCS# 6H35.51
QUARTZ WEDGE
APPARATUS
quartz wedge
202-21-E6
two polarizers
202-21-E6
overhead projector
201
DESCRIPTION
Place quartz wedge between
crossed polarizers on the overhead projector. The color
of the light that makes it through the analyzer varies with
the thickness of the quartz.
NOTES
Quartz is birefringent and so
perpendicular components of linearly polarized light travel at
different speeds through the material, emerging with a phase
difference that depends on the thickness of the material and
the wavelength of the light (since n is
wavelength-dependent). In general the light emerges
elliptically polarized.
