Quantifying metarefraction with confocal lenslet arrays

TL;DR

This paper quantifies how confocal lenslet arrays, a type of METATOY, redirect light beams, providing equations to assess their effectiveness for applications like solar concentration and exploring analogies with atomic physics.

Contribution

It derives a mathematical model for the fraction of light redirected by confocal lenslet arrays, advancing understanding of METATOYs' optical behavior.

Findings

Derived equations for light redirection fractions.

Analyzed suitability of METATOYs for solar concentration.

Discussed analogies with atomic refraction and reflection.

Abstract

METATOYs can change the direction of light in ways that appear to, but do not actually, contravene the laws of wave optics. This direction change applies only to part of the transmitted light beam; the remainder gets re-directed differently. For a specific example, namely confocal pairs of rectangular lenslet arrays with no dead area between lenslets, we calculate here the fractions of power of a uniform-intensity light beam incident from a specific (but arbitrary) direction that get re-directed in different ways, and we derive an equation describing this redirection. This will facilitate assessment of the suitability of METATOYs for applications such as solar concentration. Finally, we discuss similarities between the multiple refraction of light at the lenslet arrays and multiple refraction and reflection of cold atoms at a barrier in the presence of the light fields.