High-Speed Infrared Imaging

Molecules can emit infrared light as they transition from a high-energy vibrational state to a low-energy vibrational state. This process occurs naturally and is known as “spontaneous emission.” As temperature increases, more molecules move to high-energy vibrational states and, thus, spontaneous emission is more likely to occur leading to “brighter” infrared emission. In addition, each chemical species exhibits a unique infrared spectrum corresponding to the quantized nature of its rotational and vibrational energy levels. We are actively developing high-speed infrared imaging diagnostics which exploit these relationships to provide imaging diagnostics for temperature and chemical composition in the solid and gas phase for a variety of applications.

The video below shows infrared (left) and visible (right) imaging of a propellant sample undergoing laser-ignition. Infrared imaging provides a complete picture of the ignition event and steady flame holding, enabling us to see the propellant heat up and evaporate prior to emission of visible light.