Classical polarimetry with a twist: a compact, geometric approach

Area of Science:

• Optical physics
• Polarimetry instrumentation

Background:

• Classical polarimeters often rely on rotating components, limiting speed and robustness.
• Acquiring complete polarization data typically requires sequential measurements, hindering analysis of transient phenomena.

Purpose of the Study:

• To develop a compact, robust polarimeter with no moving parts.
• To encode full polarization information onto a single data frame for enhanced analysis.
• To enable real-time polarimetric measurements of dynamic targets.

Main Methods:

• Replaced rotating optical components with spatial variation of wave plate fast axis direction.
• Utilized a 2D data frame with a spatially varying quarter-wave plate and a fixed polarization analyzer.
• Employed spatial carrier frequencies to encode linear and circular polarization states, minimizing cross-talk.

Main Results:

• Demonstrated a novel polarimeter design capturing complete Stokes parameters in a single frame.
• Achieved maximal sensitivity to circular polarization (Stokes V) with a quarter-wave retarder.
• Spatial encoding minimized cross-talk between polarization states and offered near-achromatic performance.

Conclusions:

• The developed spatial-domain polarimeter offers a compact, robust, and single-frame acquisition solution.
• This approach overcomes limitations of sequential acquisition, enabling studies of rapidly varying targets.
• The design simplifies instrument construction and enhances applicability in diverse optical sensing scenarios.