Elimination of jitter in microlens illuminated optical probe array using a filtering layer for the optical read only memory card system

To increase the optical efficiency and areal density of optical read only memory (ROM) card system, a microlens array for generating optical probes by Talbot effects was suggested instead of the aperture array in the previous system. In the microlens array, however, the light from the corner of lens elements can cause the jitter in the optical probes. To eliminate this jitter, a filtering layer is suggested for filtering the light from the comer of lenses. To determine the opening size of filtering layer, the effect of opening size on the jitter and alignment tolerance were examined, which results in the optimum size of 10 mu m. The microlens array was integrated on the filtering layer by a UV-molding process. Finally, the elimination of jitter was verified by comparing the beam intensity distributions at the Talbot plane generated by only microlens array and microlens array with filtering layer.