Calcite Birefringence

Purpose

To demonstrate birefringence in a calcite crystal.

Equipment

Bright point source with condenser lens and iris, Letter F in baffle, calcite crystal in rotating mount, 15 cm convex lens, rotating polaroid on inserting mount.

Setup Time

5 min

Images

m8-21

Description

Light from a bright point source passes through an object (a letter F in a baffle), a calcite crystal, and a lens,which focusses the F onto a distant screen. The calcite crystal can be rotated in its baffle to show separation of the two polarization components. The rotatable polaroid at the right is inserted into the beam to demonstrate that the two component images are orthogonally polarized.

References

M. Parker Givens and Wendell V. Discher, Comments on the Optics of Birefringent Crystals, AJP 22, 379-384, (1954).Werner B. Schneider, A surprising optical property of Plexiglas rods - An unusual approach to birefringence, AJP 59, 1086-1087 (1991).