Aluminum-wire grid polarizer for a compact magneto-optic pickup device

A compact magneto-optic pickup device is required to realize magneto-optic disc systems of low cost and fast access. The key is a microminiaturized polarization component. We investigated the optimum fabrication conditions in the resonance domain for S-polarized light using electron-beam direct-writing and the liftoff method, and realized a low-loss wire-grid polarizer of Ts=80 % and Ts/Tp=30, and a high extinction ratio wire-grid polarizer of Ts=54 % and Ts/Tp=1000, for a wavelength of 0.78 /spl mu/m and a period of 0.39 /spl mu/m. These are the best values for wire-grid polarizers in the 0.8 /spl mu/m wavelength band so far reported. We studied the feasibility of using this device for polarization detection in magneto-optic disc systems by measuring the carrier-to-noise ratio (C/N).