Gigahertz-rate random speckle projection for high-speed single-pixel image classification

TL;DR

This paper introduces a GHz-rate speckle pattern generator using multimode fiber and phase modulation, enabling ultra-fast single-pixel image classification with potential for all-optical processing.

Contribution

It presents a novel ultrafast speckle generation method combining phase modulation and wavelength multiplexing for high-speed imaging applications.

Findings

Achieved 10 GHz speckle pattern modulation rate.

Successfully classified 28x28 digit images at GHz rates.

Demonstrated potential for all-optical image processing.

Abstract

Imaging techniques based on single-pixel detection, such as ghost imaging, can reconstruct or recognize a target scene from multiple measurements using a sequence of random mask patterns. However, the processing speed is limited by the low rate of the pattern generation. In this study, we propose an ultrafast method for random speckle pattern generation, which has the potential to overcome the limited processing speed. The proposed approach is based on multimode fiber speckles induced by fast optical phase modulation. We experimentally demonstrate dynamic speckle projection with phase modulation at 10 GHz rates, which is five to six orders of magnitude higher than conventional modulation approaches using spatial light modulators. Moreover, we combine the proposed generation approach with a wavelength-division multiplexing technique and apply it for image classification. As a proof-of-concept demonstration, we show that 28x28-pixel images of digits acquired at GHz rates can be accurately classified using a simple neural network. The proposed approach opens a novel pathway for an all-optical image processor.