Practical Magneto-Optic Spatial Light Modulator With Single Magnetic Domain Pixels

A 128 by 128 magneto-optic spatial light modulator (MOSLM) with single magnetic domain pixels, which is driven by using only drive lines without external bias coil, is described. The array of pixels was formed with Bi substituted iron garnet film grown by liquid phase epitaxial (LPE) method. Since the magnetic switching field of the pixels was so large owing to their growth induced magnetic anisotropy, we reduced it by annealing. Straight copper lines, which have low electrical resistance and enable to apply a homogenous magnetic field to the pixel, were used as drive lines. These improvements reduced an electric power 70% compared with conventional MOSLM and kept the pixels with a single magnetic domain after switching. Though the domain structure depended on the pulse width of current, the frame rate of 5 kHz was estimated by using optimized drive condition.