Improved sensitivity in novel scheme of magneto-optical field sensor

The sensitivity of magnetooptical detection of small fields with multidomain materials under a coherent light is discussed. For fields below the saturation, a novel scheme is proposed to increase sensitivity. Separate detection of the undeflected zeroth-order beam and diffracted beams enables their opposing responses to be added. A garnet of theta /sub F/=60 degrees (where /sub F/ is the saturation Faraday rotation) yielded a high sensitivity of more than twice that in the conventional optical configuration while a material of theta /sub F/=90 degrees offers a theoretical improvement of a factor of four.<
>