Diffraction of light using high-density magneto-optical light modulator array

We fabricated a high-density, large-scale magneto-optical (MO) light modulator array to investigate its performance for holographic display applications. The modulator comprised a magnetic nanowire for light modulation using MO Kerr effect and two hard magnets (HMs) to control the switching property of the nanowire. The magnetization direction of the designated pixels in the array was controlled by the external magnetic field, unlike a spatial light modulator, which drives arbitrary pixels with cell selection backplane transistors. Magnetization of the light modulators with HMs can be reversed using a smaller magnetic field compared with those without HMs; this enables the formation of magnetic patterns by switching only the magnetization direction of the nanowire with smaller switching field; the pattern thus obtained is predetermined and not arbitrary. A diffracted beam in a magnetic stripe pattern displayed on the array was observed as spot patterns, and their spot position was consistent with a diffraction angle of the stripe period. We fabricated a magnetic hologram using a 10  k  ×  10  k pixel array calculated by computer-generated holography and successfully reproduced a holographic three-dimensional image with a wide viewing angle.