抄録
Magnetic field optical sensors based on the Faraday effect using (TbY)IG single crystals with a striped magnetic domain structure are proposed. It is assumed that the magnetization perpendicular to the striped magnetic domains in (TbY)IG crystals occurs through a rotation of the magnetization, giving rise to a linear magnetization curve like that of Isoperm. This assumption is confirmed by optical measurements. The characteristics of a reflection- type sensor using these crystals were measured at a wavelength of 1.3 μm. The obtained sensitivity was 5.5 × 10-3 %/A/m, and a good linearity of the sensor output was obtained over a wide dynamic range between 2 A/m to 102 A/m. A noise-equivalent magnetic field of 2.1 × 10-1 A/m was also obtained. The experimental results are explained well by the proposed magnetization process model.
