Event Ellipsometer: Event-based Mueller-Matrix Video Imaging

2024-11-26

arXiv.org

AI Summary

Conventional optical ellipsometers suffer from long acquisition times, limiting them to static Mueller matrix imaging and hindering dynamic polarization characterization. To address this, we propose a novel ellipsometry-event imaging paradigm that integrates an event-based camera with a high-speed rotating quarter-wave plate. We establish a physical forward model for Mueller matrix video acquisition and develop dedicated system calibration and reconstruction algorithms. This approach uniquely unifies the event camera’s microsecond temporal resolution with ellipsometric polarization sensitivity, overcoming the fundamental static constraint of traditional methods. Experimental results demonstrate stable Mueller matrix video output at 30 fps, preserving full Stokes information while significantly enhancing dynamic polarization sensing capability. The method enables real-time, quantitative polarization dynamics monitoring—opening new avenues for applications such as in vivo tissue assessment and high-speed material stress analysis.

Technology Category

• Computer Vision: Multi-modal Vision
• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Machine Learning: Matrix & Tensor Methods

Application Category

• Security and Privacy: Large-scale security measurements
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Responsible Web: Machine-in-the-loop, human agency and autonomy

Abstract

Light-matter interactions modify both the intensity and polarization state of light. Changes in polarization, represented by a Mueller matrix, encode detailed scene information. Existing optical ellipsometers capture Mueller-matrix images; however, they are often limited to capturing static scenes due to long acquisition times. Here, we introduce Event Ellipsometer, a method for acquiring a Mueller-matrix video for dynamic scenes. Our imaging system employs fast-rotating quarter-wave plates (QWPs) in front of a light source and an event camera that asynchronously captures intensity changes induced by the rotating QWPs. We develop an ellipsometric-event image formation model, a calibration method, and an ellipsometric-event reconstruction method. We experimentally demonstrate that Event Ellipsometer enables Mueller-matrix video imaging at 30fps, extending ellipsometry to dynamic scenes.

Problem

• Capturing dynamic scenes with Mueller-matrix imaging
• Overcoming limitations of static scene ellipsometers
• Achieving real-time polarization video at 30fps

Innovation

• Event camera captures polarization changes asynchronously
• Fast-rotating quarter-wave plates enable dynamic imaging
• 30fps Mueller-matrix video for dynamic scenes