Invention:
Researchers at The University of Arizona and Hokkaido University have developed a means for polarimetric analysis that completes a full polarimetric analysis in a single measurement without any moving parts. Using a combination of two pairs of Savart Plates with a half-wave plate between them, light passing through this system creates an interference pattern that can be detected using a conventional camera. The resulting interference pattern can then be analyzed from the camera image. The ability of using this compact snapshot system with conventional cameras greatly increases the number of applications for the technology.
Background:
As light interacts with objects in the environment, the polarization parameters of light are altered in a fashion directly related to the material composition, surface roughness, and shape of the objects. A man-made object has a different polarimetric image than a natural object, for example. Conventional polarimetric instruments take measurements by moving multiple polarization filters in front of the detector, requiring multiple measurements. This approach results in problems with vibration, heat generation, and spatial registration. Moving components also increase maintenance costs and points of system failure.
Advantages:
- Polarimetric analysis is completed in one pass
- The lack of moving parts gives greater system reliability and lower maintenance cost
- By coupling a conventional camera lens with a narrow-band filter, system costs are reduced and applications are increased
Applications:
- Security surveillance
- Remote sensing
- Structure characterization
- Astronomical observation
- Terrain avoidance
