Optical “fire extinguisher”

A typical fire extinguisher puts out a fire by chemical or physical means. The “fire extinguisher” proposed in this paper is essentially a computational through-fire imaging method that features a single-pixel detector for image acquisition. This method can produce full-color fire-free video in real time. On the one hand, the method benefits from a high dynamic range, high sensitivity, and quick response given by the single-pixel detector. The single-pixel detector can accurately record the light intensity change of the fire scene without the risk of the detector’s saturation by the fire. On the other hand, the method utilizes a high-speed spatial light modulator and a programmable light source to generate color-coded, flashing structured illumination. Such spatial-temporal light modulation allows the spatial and color information of the fire scene to be encoded into a sequence of single-pixel measurements. More importantly, the fire’s component in the single-pixel measurements can be separated and computationally eliminated differentially. As such, fire-free images can be reconstructed. We demonstrate the reported optical “fire extinguisher” through a series of experiments, showcasing its potential applications in fire visual extinguishing and through-fire imaging. We also demonstrate the method’s ability to image against strong light interference.