Laser scanning microscope: differential phase images.

A beam-deflection type laser scanning microscope for differential phase contrast images using the split-detector technique is developed and the images are obtained in real time (30 images/s). The special optical design allows transfer of the pupil information necessary to the imaging of the differential phase contrast images during beam deflection and the use of acousto-optic deflectors with the associated correction system enables real time imaging. Differential phase images of surface details of crystals are simply obtained without silver coating or etching, which are indispensable in a normal DIC. Biological specimens are also observed.