Homodyne and heterodyne imaging through a scattering medium

We introduce a novel two-dimensional (2D) homodyne and heterodyne technique for imaging objects through or embedded in a scattering medium. Our imagin g approach is based on heterodyning of light with different Doppler broaden ings that is scattered from objects of two different textures or from an op aque object and a textured scattering medium. We report on the initial demo nstration of pulling signals out of noise for an object hidden behind a sca ttering medium. Enhancements of signal-to-noise ratio of the order of 50 ha ve been achieved by use of a 2D holographic phase-sensitive detector. We al so discuss the experimental feasibility of this approach for objects embedd ed in a scattering medium. (C) 2001 Optical Society of America.