Controllable transport mean free path of light in xerogel matrixes embedded with polystyrene spheres

TL;DR

This paper demonstrates how embedding polystyrene spheres in xerogel matrices allows precise control over the transport mean free path of light, enabling tunable scattering properties for potential applications like random lasers.

Contribution

It introduces a method to tune the transport mean free path of light in xerogel matrices by varying sphere concentration, supported by experimental measurements and theoretical comparisons.

Findings

Transport mean free path ranges from 90 to 600 nm.

Coherent backscattering confirms tunable scattering properties.

Comparison with Mie theory validates the control mechanism.

Abstract

Xerogel matrices, made by sol-gel techniques, are embedded with polystyrene spheres to promote multiple scattering of light. Varying the concentration of the spheres inside the matrix allows one to adjust the transport mean free path of light inside the material. Coherent backscattering measurements show that a range of transport mean free paths from 90 to 600 nm is easily achieved. The determination of the matrix refractive index permits a direct comparison to multiple scattering and Mie theory. Such tunable diffusive sol-gel derived samples can be further optimized as random laser materials.