Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Classical polarimetry with a twist: a compact, geometric approach

Published

Author(s)

William Sparks, Thomas A. Germer, Rebecca M. Sparks

Abstract

We present an approach to classical polarimetry which requires no moving parts, is compact and robust, and which encodes the complete polarization information on a single data frame, accomplished by replacing the rotation of components such as wave plates with position along a spatial axis. We demonstrate the concept with a polarimeter having a quarter wave plate whose fast axis direction changes with location along one axis of a 2D data frame in conjunction with a fixed-direction polarization analyzer, analogous to a classical rotating quarter wave plate polarimeter. The full set of Stokes parameters is obtained, with maximal sensitivity to circular polarization Stokes V if a quarter wave retarder is used. Linear and circular polarization terms are encoded with different spatial carrier frequencies which minimizes cross-talk. Other rotating component polarimeters lend themselves to the approach. Since the polarization modulation spatial frequencies do not change greatly, if at all, with wavelength such devices are close to achromatic, facilitating designs for both spectropolarimetry and polarimetric imaging. Since the polarimetric information is acquired in a single observation, transient or moving targets are accessible, loss of precision due to sequential data acquisition is avoided, and moving parts are not required.
Citation
Publications of the Astronomical Society of the Pacific
Volume
131

Keywords

polarization, Stokes vector
Created May 22, 2019, Updated January 27, 2020