Experiment: Polarization, Birefringence, and Optical Activity

Topics covered:
- Linear, circular, elliptical polarization
- Laser light polarization
- Polarization plane
- Measurement and verification of Malus' law
- Birefringence
- Ordinary / extraordinary beam
- Half-wave and quarter-wave plate
- Optically active material

In addition to intensity and wavelength, a fundamental property of light is polarization. Based on the conception of light as a transverse wave, the electric field vector propagates in a defined plane known as the polarization plane. This polarization plane can be filtered and rotated by optical elements such as polarizers or crystal retardation plates.

In this experimental kit, a green laser beam is first prepared by a polarizer, which is a polarizing filter that transmits only one polarization state of the laser beam. This well-defined polarized light is then sent through one of the half-wave or quarter-wave retardation plates, which introduces a phase shift of the electromagnetic waves and thus modifies the polarization state of the beam. Linearly, circularly, or elliptically polarized light is generated and analyzed using a second polarizing filter. The light transmitted through this polarizer is detected by a PIN photodetector, and the voltage corresponding to the light intensity is displayed on a digital multimeter. A wide variety of intensity distribution curves based on the analyzer angle and the half-wave or quarter-wave plate angles are measured in these experiments. Finally, Malus' law can be experimentally reproduced and verified.

Composition:
- 1 optical rail 0.5 m with graduated scale
- 1 green laser diode @532 nm mounted on a rider
- 1 green laser diode controller
- 2 polarizers mounted on a rider with rotatable mount
- 1 quarter-wave plate mounted on a rider with rotatable mount
- 1 half-wave plate mounted on a rider with rotatable mount
- 1 active component mounted on a rider with rotatable mount
- 1 photodiode on a rider
- 1 interferential filter
- 1 digital multimeter
- 1 set of experiment instructions (in English)