INFRARED CHEMICAL IMAGING THROUGH NONDEGENERATE TWO-PHOTON ABSORPTION IN SILICON-BASED CAMERAS

摘要

A method for infrared chemical imaging through nondegenerate two-photon absorption includes a step of providing pulsed or continuous wave radiation having pumping photons at near-infrared wavelength and providing pulsed or continuous wave radiation that having mid-infrared photons at a mid-infrared wavelength with peak intensities less than 50 W/cm2. The mid-infrared photons are directed onto a target sample. The method also includes a step of spatially and temporally overlapping the mid-infrared photons with the pumping photons. The mid-infrared photons and the pumping photons are directed onto a camera having an array or matrix of imaging devices. Characteristically, the sum of photon energy for each temporally and spatially overlapping mid-infrared photons and pumping photons is greater than or equal to the bandgap energy.