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Maximum bandwidth snapshot channeled imaging polarimeter with polarization gratings

Proceedings of SPIE - The International Society for Optical Engineering

LaCasse, Charles F.; Redman, Brian J.; Kudenov, Michael W.; Craven, Julia M.

Compact snapshot imaging polarimeters have been demonstrated in literature to provide Stokes parameter estimations for spatially varying scenes using polarization gratings. However, the demonstrated system does not employ aggressive modulation frequencies to take full advantage of the bandwidth available to the focal plane array. A snapshot imaging Stokes polarimeter is described and demonstrated through results. The simulation studies the challenges of using a maximum bandwidth configuration for a snapshot polarization grating based polarimeter, such as the fringe contrast attenuation that results from higher modulation frequencies. Similar simulation results are generated and compared for a microgrid polarimeter. Microgrid polarimeters are instruments where pixelated polarizers are superimposed onto a focal plan array, and this is another type of spatially modulated polarimeter, and the most common design uses a 2x2 super pixel of polarizers which maximally uses the available bandwidth of the focal plane array.

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TYPE Conference Poster YEAR 2016
ScopusOSTI

Ideal system morphology and reflectivity measurements for radiative-transfer model development and validation

Proceedings of SPIE - The International Society for Optical Engineering

Kulp, Thomas J.; Sommers, R.L.; Krafcik, Karen L.; Mills, Bernice E.; Reichardt, Thomas A.; Dorrance, J.K.; Lacasse, C.F.; Fuerschbach, Kyle H.; Craven, Julia M.

This paper describes measurements being made on a series of material systems for the purpose of developing a radiative-transfer model that describes the reflectance of light by granular solids. It is well recognized that the reflectance spectra of granular materials depend on their intrinsic (n(λ) and k(λ)) and extrinsic (morphological) properties. There is, however, a lack of robust and proven models to relate spectra to these parameters. The described work is being conducted in parallel with a modeling effort1 to address this need. Each follows a common developmental spiral in which material properties are varied and the ability of the model to calculate the effects of the changes are tested. The parameters being varied include particle size/shape, packing density, material birefringence, optical thickness, and spectral contribution of a substrate. It is expected that the outcome of this work will be useful in interpreting reflectance data for hyperspectral imaging (HSI), and for a variety of other areas that rely on it.

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TYPE Conference Poster YEAR 2016
ScopusOSTI
Results 26–46 of 46
Results 26–46 of 46