First evidence for the linear magnetic birefringence of the reflecting surface of interferential mirrors.

Abstract. In this letter we report the first evidence of the magnetic anisotropy of the refraction index (Cotton-Mouton effect) induced by the magnetic field on the reflecting surface of very high reflectivity interferential mirrors. An apparatus to measure small linear magnetic birefringences has been set up. It is based on a high finesse Fabry-Perot cavity, to which a Nd:YAG laser is frequency locked, and on a 1.1 T permanent dipole magnet. The ellipticity acquired by a linearly polarized light beam per reflection is negative and about 10[sup -9]. [ABSTRACT FROM AUTHOR]