Optical tomography in scattering media: image enhancement using redundant apertured optics [biological application]

A method for using tomographic measurement to enhance the ratio of short-path-length light to highly scattered light is presented. The enhancement is accomplished by imaging a source aperture onto a detector aperture, thereby restricting the light path to the imaging lens collection cone. Reduced collection of multiple scattered light is demonstrated using time-resolved measurements of scattering media with and without the redundant aperture present. With the redundant aperture in place, significant reduction in the amount of scattered light collected with long path lengths is shown. Also, the overall variation of the path lengths is smaller. This suggests that more accurate optical tomographic reconstructions an be obtained using the redundant aperture configuration