Evaluation of magneto-optic pixels in spatial light modulators composed of magnetophotonic crystal by means of a magneto-optical microscope with OPO wavelength variable laser system

To evaluate magnetization process of pixels in magneto-optic spatial light modulators (MOSLMs) with one-dimensional magnetophotonic crystals (MPCs), a magneto-optic microscope composed of optical parametric oscillator (OPO) wavelength variable laser system was developed. The observation results show that the microscope is effective for accurate determination of magneto-optic rotation angle of samples exhibiting strong wavelength dependence, such as the case of MPCs, because of the very narrow wavelength width of the OPO laser system. The magnetization process of the MPC pixels was found to be unique, where tiny magnetic clusters change their direction almost irrespectively to each other, and the resultant pixel exhibit gray-scale color depending on the number of magnetic clusters whose magnetization switched its direction. © 2010 The Institute of Electrical Engineers of Japan.