A Mega-FPS low light camera

TL;DR

This paper introduces a novel interlaced fast kinetics imaging technique enabling ultra-fast burst video capture at up to 3.33 million frames per second with single-photon sensitivity, using a modified EMCCD camera.

Contribution

The paper presents a new imaging method that leverages EMCCD dynamics and a tilted lens array to achieve unprecedented frame rates and sensitivity in high-speed imaging.

Findings

Achieves up to 3.33 million fps video capture.

Maintains 50% contrast at 1.61 MHz modulation frequency.

Demonstrates imaging of spatial patterns with 11x15 resolution.

Abstract

From biology and astronomy to quantum optics, there is a critical need for high frame rate, high quantum efficiency imaging. In practice, most cameras only satisfy one of these requirements. Here we introduce interlaced fast kinetics imaging, a technique that allows burst video acquisition at frame rates up to 3.33 Mfps using a commercial EMCCD camera with single-photon sensitivity. This approach leverages EMCCD's intrinsic fast row transfer dynamics by introducing a tilted lens array into the imaging path, creating a spatially distributed grid of exposed pixels, each aligned to its own column of the sensor. The remaining unexposed pixels serve as in-situ storage registers, allowing subsequent frames to be captured after just one row shift operation. Our interlaced fast kinetics camera maintains 50% contrast for square wave intensity modulation frequencies up to 1.61 MHz. We provide benchmarks of the video performance by capturing two dimensional videos of spatially evolving patterns that repeat every 2$\mu$s, with spatial resolution of 11$\times$15 pixels. Our approach is compatible with commercial EMCCDs and opens a new route to ultra-fast imaging at single-photon sensitivity with applications from fast fluorescence imaging to photon correlation measurement.