Time-gated harmonic imaging through scattering media

Summary form only given. We have demonstrated that time-gated upconversion can be used in a nonscanning geometry for background-free imaging of stationary objects with millimeter resolution. Our results were obtained using a crossed beam configuration, but collinear (inline) geometries are feasible in type II geometries. No image processing was necessary to obtain the results presented here. Images were obvious to the naked eye at short gate delays. This scheme is expected to be well-adapted to imaging problems involving moving scattering media because the nonlinear process utilized to reconstruct the image is an intensity correlation, which should be insensitive to phase variations of scattered fields.