Two-dimensional phase imaging in the scanning optical microscope

It is shown that an image of absolute object phase may be produced by integrating a differential phase contrast image produced by a large area split detector. Even though integration is being carried out only along the scan lines, a full 2-D phase image is produced by surrounding the object with a medium of uniform path length and resetting the integrator at the beginning of each scan line. Images of a buccal epithelium cell demonstrate the technique.