An integrated imaging detector of polarization and spectral content

Abstract

A new type of image detector has been designed to simultaneously analyze the polarization of light at all picture elements in a scene. The Integrated Dual Imaging Detector (IDID) consists of a polarizing beamsplitter bonded to a chargecoupled device (CCD), with signal-analysis circuitry and analog-to-digital converters, all integrated on a silicon chip. It should be capable of 1 : 10 4 polarization discrimination. The IDID should simplify the design and operation of imaging polarimeters and spectroscopic imagers used, for example, in atmospheric and solar research. Innovations in the IDID include (1) two interleaved 512 x 1024-pixel imaging arrays (one for each polarization plane); (2) large dynamic range (well depth of 10 6 electrons per pixel); (3) simultaneous readout of both images at 10 million pixels per second each; (4) on-chip analog signal processing to produce polarization maps in real time; (5) on-chip 10-bit A/D conversion. When used with a lithium-niobate Fabry-Perot etalon or other color filter that can encode spectral information as polarization, the IDID can collect and analyze simultaneous images at two wavelengths. Precise photometric analysis of molecular or atomic concentrations in the atmosphere is one suggested application. When used in a solar telescope, the IDID will charge the polarization, which can then be converted to maps of the vector magnetic fields on the solar surface.

Sub-percent characterization and polarimetric performance analysis of commercial micro-polarizer array detectors

“…Rust in 1995. 6 One of the first publications to describe the fabrication of a pixelated polarizer filter, and successively create a micropolarizer array detector were Kalayjian et al in 1996. 7 Since 2D techniques for this polarization pattern did not exist yet at the time, they kept to 1D strips of chemically etched polarizing films on top of the photodiode array, which were only sensitive to the first two Stokes parameters.…”

Performance comparison of division of time and division of focal plan polarimeters

“…Division of focal plane (DoFP) polarimetry is an emerging technique using a polarization filter array (PFA). 7 A spatial modulation in the focal-plane array permits to sample the intensities of the light field through several polarizing directions θ. The most common PFA camera embeds a 4-channel sensor, 8 which combines four angles of analysis, equally-distributed between 0°and 180°(θ = 0°, 45°, 90°, 135°).…”