Low error of garnet optical sensor induced by spin Hall effect

Abstract The Polarization properties of a linearly polarized laser beam reflected from garnet/Au, Ta/Nd2Fe14B/Ta/garnet/Au are studied by a Thorlabs PAX 5710 IR3 polarimeter undser external magnetic and direct current (DC) electric fields. The Nd2Fe14B, Ta and Au films are prepared by a DC magnetron sputtering method. The magnetic domains of the garnet films are obtained by a polarized light microscope. The magnetic domains in different garnet films show different distributions. The error of the Stokes parameter S1 is used to characterize the results. The S1 of the linearly polarized laser beam reflected from garnet/Au and Ta/Nd2Fe14B/Ta/garnet/Au shows different trends with the magnetic and electric fields. The maximum error S1 of garnet/Au is 0.005%, while the maximum error S1 of Ta/Nd2Fe14B/Ta/garnet/Au is 0.003%, when the external DC voltage increases from 0 to 2.5V, and the magnetic field increases from 0 to 100Oe. The low error may be induced by the spin Hall effect of garnet and Au. It is very important for the manufacture and design of optical current and voltage sensors.