Imaging in diffuse media with ultrafast degenerate optical parametric amplification.

We demonstrate the application of a subpicosecond optical parametric amplifier working at degeneracy to imaging in diffuse media. This optical parametric amplifier exhibits small-signal gains greater than 10(4), thereby acting as a high-gain ultrafast amplifying gate. We have used it to construct the image of a grid pattern hidden behind 20 mean free paths of a highly diffusing solution of latex microspheres with a spatial resolution of 200 microm.