Ray-tracing simulation method using piecewise quadratic interpolant for aspheric optical systems

We present a new method for precise ray-tracing simulation considering form errors in the fabrication process of aspheric lenses. The Nagata patch, a quadratic interpolant for surface meshes using normal vectors, is adopted for representing the lens geometry with mid-spectral frequencies of surface profile errors. Several improvements in the ray-patch intersection calculation and its acceleration technique are also proposed. The developed algorithm is applied to ray-tracing simulation of optical disk pickup aspheric objectives, and this technique requires 105 to 109 times fewer patches than a polygonal approximation. The simulation takes only several seconds on a standard PC. OCIS codes: 000.4430, 080.0080, 080.1753, 220.1250, 220.2740, 240.0240.