High-speed real-time single-pixel microscopy based on Fourier sampling

TL;DR

This paper introduces a high-speed single-pixel imaging method using Fourier spectrum acquisition and inverse Fourier transform, enabling real-time image reconstruction and applications in fast dynamic phenomena observation.

Contribution

It proposes a novel Fourier-based single-pixel imaging technique with phase-shifting sinusoidal illumination, significantly reducing reconstruction time compared to traditional compressed sensing methods.

Findings

Achieved 625 kHz frame rate in experiments.

Demonstrated high-throughput flow cytometry at 100,000 cells/sec.

Enabled real-time image reconstruction with 10% compression ratio.

Abstract

Single-pixel cameras based on the concepts of compressed sensing (CS) leverage the inherent structure of images to retrieve them with far fewer measurements and operate efficiently over a significantly broader spectral range than conventional silicon-based cameras. Recently, photonic time-stretch (PTS) technique facilitates the emergence of high-speed single-pixel cameras. A significant breakthrough in imaging speed of single-pixel cameras enables observation of fast dynamic phenomena. However, according to CS theory, image reconstruction is an iterative process that consumes enormous amounts of computational time and cannot be performed in real time. To address this challenge, we propose a novel single-pixel imaging technique that can produce high-quality images through rapid acquisition of their effective spatial Fourier spectrum. We employ phase-shifting sinusoidal structured illumination instead of random illumination for spectrum acquisition and apply inverse Fourier transform to the obtained spectrum for image restoration. We evaluate the performance of our prototype system by recognizing quick response (QR) codes and flow cytometric screening of cells. A frame rate of 625 kHz and a compression ratio of 10% are experimentally demonstrated in accordance with the recognition rate of the QR code. An imaging flow cytometer enabling high-content screening with an unprecedented throughput of 100,000 cells/s is also demonstrated. For real-time imaging applications, the proposed single-pixel microscope can significantly reduce the time required for image reconstruction by two orders of magnitude, which can be widely applied in industrial quality control and label-free biomedical imaging.