Images describing polarimetric characteristics of objects are more and more used when studying complex scenes. In some cases, only the depolarization phenomenon, mostly due to scattering, proves of interest and estimating the degree of polarization ͑DOP͒ is sufficient. For a linearly polarized beam under normal incidence, when the materials in the scene exhibit neither birefringence nor dichroism, this comes down to an intensity measurement in two crossed directions. Nevertheless, the classical optical setup, consisting mainly of a rotating polarizer used as a polarization state analyzer, gives good-quality images, but cannot provide dynamic information. In this paper, we propose to use a ferroelectric liquid-crystal modulator in an imaging polarimeter. We demonstrate the use of this modulator as a polarization state analyzer for frame rates up to about 400 Hz. Provided a fast camera is used, we show that the polarimeter allows us to surpass the classical video frame rate. We propose a setup using a rapid CCD camera ͑up to 233 Hz͒. Images in DOP are of very high quality and hold their own against images obtained with a classical polarizer. With a faster camera, we were able to obtain images at up to 400 Hz.

This paper describes the implementation of an imaging polarimeter using a single ferroelectric liquid crystal light modulator. It provides partial imaging Stokes information at 234 Hz, much faster than polarimeters using nematic light modulators. This information is obtained for dynamic scenes in reflection or transmission. Partial Stokes information contains the first three Stokes parameters. With this information, imaging of the linear degree of polarization and of the angle of polarization can be obtained and imaging linear depolarization can be quantified.

No abstract

No abstract

No abstract