Event Ellipsometer: Event-based Mueller-Matrix Video Imaging
This work addresses the problem of capturing detailed polarization-based scene information in dynamic settings for applications in optical imaging and sensing, representing a domain-specific advancement.
The paper tackles the limitation of existing optical ellipsometers, which are slow and only capture static scenes, by introducing Event Ellipsometer, a method that enables Mueller-matrix video imaging at 30fps for dynamic scenes.
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.