Single-Shot Speckle Correlation for Target Discrimination

Abstract When a light beam interacts with a target, the resulting speckle pattern encodes the target’s spatial information, which is otherwise challenging to decode directly. Here, we demonstrate that the target information can be discriminated by performing second-order intensity correlation analysis within a single speckle pattern. Our technique requires neither thousands of patterns nor complex algorithms but relies solely on correlating intensities along different orientations within one shot. This makes our method remarkably simple and fast. In a proof-of-principle experiment, we successfully differentiated between three distinct targets: a pinhole, a single slit, and a double slit. This work provides an effective framework for rapid target discrimination and has potential applications in high-speed image processing.