Abstract:

Mid-infrared (MIR) imaging is an indispensable analytical tool for its ability to characterize the morphology and chemical composition of samples simultaneously. However, instrumentation surrounding the technique limits its widespread implementation. Array detectors designed for MIR detection fail to quickly produce high-resolution images over the entire MIR spectrum, with the unfortunate tradeoff between imaging speed and pixel density. This is unlike visible or near-infrared imagers, which are sensitive, fast, and ever-increasing in definition. This thesis offers a new approach to take advantage of these mature detector technologies, where the information encoded into the MIR beam is converted directly into photoelectrons through the nonlinear optical response of the camera chip itself. Through nondegenerate two-photon absorption, we demonstrate high-speed widefield MIR imaging in high pixel-density visible and NIR cameras for the first time. Additionally, we leverage the physical properties of ultrashort laser pulses to provide hyperspectral imaging and 3D imaging using this technique.