Effects of a magnetic field on the optical properties of dielectric mirrors

Abstract

We have measured the changes in the polarization state of a monochromatic (λ=514.5 nm) light beam on reflection at normal incidence by a multilayer dielectric mirror placed in a time-modulated magnetic field. The dominant effect is a Faraday rotationΦ≃3.7×10⁻¹⁰ rad/G. The sensitivity (around 40Hz) obtained is$\simeq 6 \times 10^{ - 9} {\text{ rad/}}\sqrt {{\text{Hz}}}$ which is dominated by the shot-noise limit (100 mW of light power).