Modelling Surface Light Scattering in the Context of Freeform Optical Design

TL;DR

This paper introduces a new model for surface light scattering in freeform optical design, using energy conservation and optimal transport theory to enable traditional reflector design methods to account for scattering effects.

Contribution

It presents a novel scattering model based on energy conservation and optimal transport, facilitating the integration of scattering into freeform optical design processes.

Findings

The model expresses scattered light as a convolution of a scattering function and specular distribution.

Deconvolution allows traditional reflector design methods to incorporate scattering effects.

Applicable to isotropic scattering in symmetric optical systems.

Abstract

We present a novel approach of modelling surface light scattering in the context of freeform optical design. The model relies on energy conservation and optimal transport theory. For isotropic scattering in cylindrically or rotationally symmetric systems with in-plane scattering, the scattered light distribution can be expressed as a convolution between a scattering function, which characterises the optical properties of the surface, and a specular light distribution. Deconvolving this expression allows for traditional specular reflector design procedures to be used, whilst accounting for scattering.