Simulation of polarized optical speckle fields: effects of the observation scale on polarimetry

Abstract

In this paper, we propose the simulation of polarized speckle fields using the Stokes formalism, which allows the description of partially polarized electromagnetic waves. We define a unique parameter which determines the partial decorrelation of the involved fields, allowing to simulate the polarized speckles produced by all types of scatterers, from simple to multiple scatterers. We validate this model by comparison with experimental measurements. We use that simulation model to study the impact of the imaging device parameters on polarimetric measurements: first we emphasize a limit of resolution on retardance measurements, then we study the spatial depolarization, which appears when an observer is measuring any space-variant polarization map.

Spectralon spatial depolarization: towards an intrinsic characterization using a novel phase shift distribution analysis

“…Thus for all the samples, I x and I y are two independent speckle fields [25], with equal mean intensities. Reciprocally, in order to modelize the polarized subjective speckle produced by any kind of Lambertian scatterer (from a simple to a multiple scatterer), a simple way is to sum two independent speckles with the same mean intensity, orthogonally polarized and with partially correlated phase planes, the scattering regime depending on that partial correlation [26].…”

Broadband loss-less optical thin-film depolarizing devices

“…These last Eqs. (15) and (16) allow to calculate the reflected field E r from the knowledge of the spatial variations of reflection at the sample entrance.…”

“…For that one can use Eqs. (15) or (16), depending on whether there is an imaging system between the sample and the detector. For the sake of simplicity we will here focus on Eq.…”

“…Although one can easily transform the polarization state of light into another arbitrary state (both with dop = 1), the converse situation is less common and is often accompanied by optical losses and a reduction of spatial or temporal coherence [13][14][15][16][17][18][19]. Hence different kinds of devices and systems were designed and built to reach this depolarization function, on the basis of [20,21].…”