Upconverting time gate for imaging through highly scattering media

Abstract

We report the use of sum- and difference-frequency generation for two-dimensional upconversion time gating. Using difference-frequency generation, which can provide gain as well as upconversion (as an optical parametric amplifier), we have imaged through a scattering medium with an attenuation of exp(-25), using 1 mJ of energy from a single laser pulse.