COTTON-MOUTON EFFECT MEASUREMENT WITH THE FABRY-PEROT EIGENSTATES

We show that, using the eigenstates of a high-finesse Fabry-Perot cavi ty, we can measure the small Cotton-Mouton birefringence of gases with a simple tabletop apparatus. It requires only modest magnetic fields (B<1 T) and uses an ultrastable Zerodur high-finesse optical cavity. T he method is validated by the measurement of the Cotton-Mouton constan t of air and a sensitivity of 2.5 X 10(-9) rad is obtained for the sin gle pass birefringence. (C) 1998 American Institute of Physics. [S0003 -6951(98)04634-8].