Mean path length inside non-scattering refractive objects

Abstract

It has recently been argued that the geometric-optics mean path length of rays inside a refractive object under Lambertian illumination is independent of the scattering strength of the medium [Savo et al., Science 358, 765 (2017)]. We here show that it is in fact different in the case of zero-scattering. We uncover and explain the role of trapped ray trajectories in creating this unexpected discontinuity from zero- to low-scattering. This allows us to derive new analytic results for the zero-scattering mean path length of simple refractive shapes. This work provides a fresh perspective on the study of path length inside refractive objects, with possible applications in for example the study of scattering by large particles or the design of optical systems.

arXiv comment12 pages, 10 figures, includes supplementary information

References in corpus (6)

• Mean path length invariance in multiple light scattering
• Path length enhancement in disordered media for increased absorption
• Analytical Description of a Luminescent Solar Concentrator Device
• Tiling large areas with luminescent solar concentrators: geometry effects
• Invariance property in inhomogeneous scattering media with refractive-index mismatch
• Invariance property in scattering media and absorption