Numerical Simulation Method for a Liquid-Crystal Aberration Compensation Device

We have developed a numerical simulation method on the basis of the ray tracing technique to evaluate a liquid-crystal (LC) spherical aberration compensation device for next-generation high-capacity optical memory devices. We numerically evaluated the performance and the tolerance of the LC device and showed its adequate capability to compensate the spherical aberration due to the nonuniformity of the disc cover layer thickness. Using the simulation method, we numerically examined the possibility of using LC devices to compensate the large spherical aberration due to the layer jump of the dual-layer optical disc and determined that the gradation-type LC device can be used for dual-layer optical recording.