Optimized Stokes imaging for highly resolved optical speckle fields, Part II: optimal acquisition and estimation strategies

Probing the enpolarization phenomenon in a speckle pattern using a microwave photonics-inspired approach

We report how Stokes polarimetry of a highly resolved optical speckle pattern coupled to an original microwave photonics-inspired experimental approach allows new light to be shaded on the so-called enpolarization phenomenon, which consists in the local increase of the light degree of polarization (DOP) inducing a high average DOP value after interaction of unpolarized light with a totally depolarizing sample.

Optimized Stokes imaging for highly resolved optical speckle fields, Part I: optimized experimental setup

In this first article of a three-part series focusing on the Stokes polarimetry of optical speckle fields resolved at the individual speckle grain scale, a review of the state-of-the-art techniques for such experimental investigations is provided. An optimized experimental setup is then extensively described, which allows polarimetric Stokes measurements on such complex interference patterns to be carried out at each location of the speckle field without disturbing the wavefront. Specific calibration procedures are also described to provide an estimation of the reliable polarimetric properties of light across a resolved speckle field.

Optimized Stokes imaging for highly resolved optical speckle fields, Part III: topological analysis of polarimetric state distributions with optimized data representations

In this last article of a three-paper series focusing on Stokes polarimetry of optical speckle fields resolved at the individual speckle grain scale, experimental results are provided on test samples of varying nature and polarization properties, and are analyzed extensively. For this purpose, a review of the classical ways of displaying Stokes polarimetric information is provided. Then, some original alternative graphical representations are introduced that ensure optimal readability and interpretability of the Stokes imaging data in the context of speckle field polarimetry, and it is shown how they can be adapted to various observation scales. Finally, these tools are implemented in order to provide a topological analysis of the distribution of the states of polarization across a speckle pattern, and in the vicinity of polarimetric singularities of the field.