LAUSR

Recognition, comparison, and analysis of large patterns or images are computationally intensive tasks that can be more efficiently addressed by inherently parallel optical techniques than sequential electronic data processing. However, existing all-optical image processing and pattern recognition methods based on optical nonlinearities are limited by an unavoidable trade-off between speed and intensity requirements. Here we propose and experimentally demonstrate a technique for recognition and analysis of binary images that is based on the linear interaction of light with light on a lossy metamaterial beam splitter of substantially subwavelength thickness. Similarities and differences between arbitrarily complex binary images are mapped directly with a camera for real-time qualitative analysis. Regarding quantitative analysis, agreement, disagreement, and any other set operation between the patterns can be determined from power measurements acquired with a photodetector. In contrast to nonlinear technique...