Designing Illumination Lenses and Mirrors by the Numerical Solution of Monge-Amp\`ere Equations

TL;DR

This paper extends a B-spline collocation numerical method to solve nonlinear Monge-Ampère equations for designing free-form optical lenses and mirrors that produce specified illumination patterns, verified through ray tracing.

Contribution

It introduces an extended collocation approach for inverse refractor problems, including boundary condition handling, advancing numerical solutions for complex optical surface design.

Findings

Numerical solutions for refracting and reflecting surfaces successfully produced desired illumination patterns.

Method effectively handles boundary conditions and constraints in nonlinear PDEs.

Ray tracing confirms the accuracy of the designed optical surfaces.

Abstract

We consider the inverse refractor and the inverse reflector problem. The task is to design a free-form lens or a free-form mirror that, when illuminated by a point light source, produces a given illumination pattern on a target. Both problems can be modeled by strongly nonlinear second-order partial differential equations of Monge-Amp\`ere type. In [Math. Models Methods Appl. Sci. 25 (2015), pp. 803--837, DOI: 10.1142/S0218202515500190] the authors have proposed a B-spline collocation method which has been applied to the inverse reflector problem. Now this approach is extended to the inverse refractor problem. We explain in depth the collocation method and how to handle boundary conditions and constraints. The paper concludes with numerical results of refracting and reflecting optical surfaces and their verification via ray tracing.