Optical Birefringence Measurement by Means of a Rotating Analyzer with Application to Kerr Effect
TEXAS UNIV AT AUSTIN ELECTRONICS RESEARCH CENTER
Pagination or Media Count:
A rotating analyzer method was developed for rapid measurement of the ellipticity of polarized light as produced by optically birefringent materials. A plane optical analyzer, in the form of a Glann-Thompson prism, is placed in the light path ahead of an electrical photodetector and is continuously rotated on an axis coincident with the light path. For light having either constant or slowly varying ellipticity, this lead to sinusoidally time varying electrical signals which bear a simple relationship to the eccentricity and orientation of the ellipticity. In application to the Kerr effect, the ellipticity results from passage of circularly polarized light through the Kerr cell. For sinusoidally time varying electric fields applied to the Kerr cell, the optical retardation of the cell contains both steady and alternating components. These components are separated in the frequency structure of the electrical photoresponse. In this application the method may be used to discriminate against effects of light intensity fluctuations and small residual birefringence in windows. This permits measurement of the Kerr effect in materials having very small Kerr constants.
- Test Facilities, Equipment and Methods