Ray tracing of an aspherical lens with antireflective subwavelength structured surfaces

Abstract

A method of ray tracing for an aspherical lens with subwavelength periodic structured surfaces has been developed. The ray tracing in the antireflective subwavelength structure is based on the group velocity of the Bloch wave. Transmittance and phase delay for the surface structure are determined with rigorous coupled wave analysis. Calculated wavefront aberration was smaller than 20 mlambda for an aspherical lens with numerical aperture of 0.6. For a lens with a higher numerical aperture, the wavefront aberrations increase drastically.