ABSTRACT
A simple upconversion scheme utilizing 40-fs pulses is shown to permit high-contrast imaging of objects obscured by a highly scattering medium when no ballistic component is evident in the scattered light and imaging is performed with any portion of the scattered light pulse. We present a time-gated, inherently low-pass spatially filtered imaging method that minimizes signal-averaging requirements and greatly facilitates imaging under severe scattering (turbid) conditions.
ABSTRACT
A spectral-holography application called spectral-decomposition holography forms a recorded image according to optical path length. In this method all wavelength components of a broad-spectrum source simultaneously backlight a nonscattering binary-phase object. A spectral hologram is thus recorded. Subsequent computer processing recovers temporally discriminated images.
ABSTRACT
Absorbers were imaged through a highly scattering material by application of spectral holography. A broad-spectrum source forms the spectral hologram of light transmitted by a diffuser, and computer processing reconstructs a series of images of the diffuser as it would have appeared with scattered light that traveled different path lengths. One of these reconstructed images is certain to be an image formed with first-arriving light and is therefore an image of the diffuser as seen with the least-scattered light. Experimental results present an image of an absorber hidden by a diffuser in which the gating was done by computer.
