Effect of an annular pupil on confocal imaging through highly scattering media.

We report on confocal scanning imaging through highly scattering media. Various practical effects including those of the annular pupils and the size of the confocal pinhole as well as of the numerical aperture of objectives on the image quality are examined xperimentally. The combination of an annular objective with a finitesized detector may prove advantageous for improving image quality.