We demonstrate a photon-sensitive, three-dimensional (3D) camera by active near-infrared illumination and fast time-of-flight gating. It uses picosecond pump pulses to selectively upconvert the backscattered photons according their spatiotemporal modes via sum-frequency generation in <mml:mi...

Lead selenide (PbSe) emerged 70+ years ago for its unique photoconductive sensitivity to the mid-wave infrared (MWIR) spectrum; however, new and exciting research continues ignite interest in this material day.