Ultrafast imaging in combustion

Abstract

The evolution of imaging technologies—from Galileo’s telescope to modern high-speed cameras—has significantly advanced scientific exploration. While spatial resolution has traditionally been the focus, the ability to capture events at extremely short time scales, or temporal resolution, is equally crucial for observing ultrafast phenomena such as shockwaves, droplet dynamics, and plasma discharges. Traditional high-speed cameras, however, face limitations in frame rate, cost, and data volume. This thesis explores Compressed Imaging, a transformative approach that overcomes these limitations by capturing temporally encoded information in a single shot and reconstructing it computationally into high-speed video. We focus on Compressed Optical Shearing Ultrafast Photography (COSUP)—a cost-effective and simple setup that leverages compressed sensing principles to achieve ultrafast imaging without requiring expensive or complex hardware. By developing and optimizing a COSUP-based imaging system, this work demonstrates the ability to record high-temporal-resolution videos of fast physical phenomena using a single frame. The methodology reduces experimental repetition and data overhead, offering a practical solution for high-speed imaging in resource-constrained environments. The results underline COSUP’s potential as a powerful tool in scientific diagnostics, fluid dynamics, and other domains where capturing transient events is critical.