Possibility of phase-contrast pickup head for two-layered optical disk

摘要

Zernike phase-contrast method is proposed for its application to optical pickup head for the two-layer optical disk. The most attractive feature of this proposed approach is that a very simple architecture can be fabricated for simultaneous readout of both layers with only one objective lens. After giving the basic theoretical analyses of Zernike phase-contrast method, we constructed one feasible system based on this method and discussed the influences caused by the possible phase change of the high order spectrum and the finite aperture. The experimental demonstration of the proposed system is given.