Designing partial Mueller matrix polarimeters

Abstract

When using a MMP for a detection or identification task, a user considers certain elements of the Mueller matrix. The usual way of performing this task is to measure the full Mueller matrix and discard the unused elements. For polarimeter designs with speed, miniaturization, or other constraints it may be desirable to have a system with reduced dimensionality that measures only the important elements of the Mueller matrix as efficiently as possible. In this paper, we develop a framework that allows partial MMPs to be analyzed. Quantitative metrics are developed by considering geometrical relationships between the space spanned by a particular MMP and the space occupied by the scene components. The method is generalized to allow the effects of noise to come into the equation when noise performance is important as well.

When is polarimetric imaging preferable to intensity imaging for target detection?

“…Active polarimetric imaging systems illuminate the scene with a controlled polarization state and analyze the polarization state of the light scattered by the scene. A lot of work has been done on the optimization of the illumination and analysis states for different signal processing tasks, such as estimation of the Stokes vector [8][9][10][11][12] or discrimination of targets from backgrounds [13][14][15][16]. However, these demonstrations of optimality usually assume that the illumination and analysis polarization states are purely polarized, and the problem remains to determine whether it is preferable to illuminate the scene with purely polarized or partially polarized light.…”

“…In target detection applications, the relevant efficiency criterion is contrast (or discrimination ability) between a target and a background. Analysis of the contrast and its optimization in polarimetric images have been investigated in the radar [13,17] and in the optics [14][15][16]18] communities. It has been shown recently that, in the presence of additive Gaussian noise and when the illumination is purely polarized, the polarimetric imaging architecture that maximizes the contrast between a target and a background consists of acquiring a single intensity image with optimized illumination and analysis states [19].…”

Fully tunable active polarization imager for contrast enhancement and partial polarimetry

“…However, these images have to be acquired with illumination and analysis states that depend on the scene and may lie anywhere on the Poincaré sphere. In other cases, it may be sufficient to extract only partial information, such as particular coefficients or set of coefficients of the Mueller matrix [18,19]. In such applications, the fixed states adapted to acquisition of the whole Mueller matrix may not be optimal for acquiring the required information with a minimum number of measurements.…”