title: Fast GPU-based ray tracing in radial GRIN lenses.
abstract: This paper describes that in ray tracing of a radial gradient-index (GRIN) lens, analysis with a graphics processing unit (GPU) can complete faster than analysis with a central processing unit (CPU). The refractive index of the radial GRIN lens varies in the direction perpendicular to the optical axis. We prepare two types of the refractive index distribution for the radial GRIN lens. One type of distribution is represented by the power series expansion equation and the other is an arbitrary distribution type represented by a cubic spline interpolation curve. Although the performance of ray tracing with these distribution representations varies between representations, in both representations, the analysis with a GPU is about 19 times (on average) faster than that with a CPU. The average GPU effective performance is 90% and 40% when the refractive index distribution is given by the power series expansion equation and spline interpolation curve, respectively. These increased performances indicate that ray tracing with these distributions is very effective for the GRIN lens illumination and rendering analyses, which have to trace a significant number of rays.
authors.forename: Shuma
authors.initials: S
authors.lastname: Horiuchi
authors.forename: Shuhei
authors.initials: S
authors.lastname: Yoshida
authors.forename: Manabu
authors.initials: M
authors.lastname: Yamamoto