Extended Depth of Field Through Wavefront Coding

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Imaging Systems Laboratory, Department of Electrical Engineering
University of Colorado, Boulder, Colorado 80309

Extended Depth of Field Through Wavefront Coding

Edward R. Dowski, Jr. and W. Thomas Cathey

Tue Oct 31 12:24:24 MST 1995


We have designed an optical/digital system that delivers near diffraction limited imaging performance with a large depth of field. This system is the standard incoherent optical system modified by a phase mask, with digital processing of the resulting intermediate image. The phase mask alters or codes the received incoherent wavefront in such a way that the PSF and OTF do not appreciably change as a function of misfocus. Focus independent digital filtering of the intermediate image is used to produce a combined optical/digital system that has a nearly diffraction limited PSF. This high resolution extended depth of field is obtained through the expense of increased dynamic range of the incoherent system. We use both the ambiguity function and the method of stationary phase to design these phase masks.
Key Words: Extended Depth of Field, Extended Depth of Focus, Wavefront Coding

Ed Dowski
Tue Oct 31 12:23:40 MST 1995