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An Imaging Polarimeter(IMPOL) for multi-wavelength observations

A. N. Ramaprakash·Ranjan Gupta·A. K. Sen·S. N. Tandon
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Abstract

Taking advantage of the advances in array detector technology, an imaging polarimeter (IMPOL) has been constructed for measuring linear polarization in the wavelength band from 400-800 nm. It makes use of a Wollaston prism as the analyser to measure simultaneously the two orthogonal polarization components that define a Stoke's parameter. An achromatic half-wave plate is used to rotate the plane of polarization with respect to the axis of the analyser so that the second Stoke's parameter also can be determined. With a field of view correponding to about 30x30 sq. mm for a 1.2 m, f/13 telescope, a sensitive, liquid-nitrogen cooled CCD camera as the detector and a built-in acquisition and guidance unit, the instrument can be used for studying stellar fields or extended objects with an angular resolution close to 2 arcsec. The instrumental polarization is less than 0.05% and the accuracies of measurement are primarily limited by photon noise for typical observations.

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A. N. Ramaprakash, Ranjan Gupta, A. K. Sen, S. N. Tandon. 1997-01-08. An Imaging Polarimeter(IMPOL) for multi-wavelength observations. https://doi.org/10.1051/aas%3A1998148

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