Abstract

An intracavity polarimeter for measuring small optical anisotropies is described. It is based on an optically pumped sodium dimer ring laser that supports two counterpropagating, orthogonally polarized modes. The optical anisot-ropy of an intracavity sample is detected by its effect on the beat frequency between the two modes. An analysis of the noise shows that a phase-retardation sensitivity of 6 × 10⁻⁸ rad can be achieved. A preliminary measurement of the Kerr effect in CO₂ is reported.

© 1988 Optical Society of America