Holographic microscope with suppression of coherent noise

Claim 1

A holographic microscope for recording and reconstructing of holograms and for interferometric investigation comprising laser illumination means for producing a coherent laser beam, a device for suppression of coherent noise by unidirectional averaging, a member splitting the laser beam into a reference beam and an object beam, a first optical system for directing said object beam to a holographic recording material along a first path and for forming an image of an object on said recording material, and a second optical system similar to said first optical system for directing said reference beam to said recording material along a second path angularly displaced from said first path and having a length substantially equal to the length of said first path, the axes of said first and second paths lying in a plane, said device for unidirectional averaging of the coherent noise being positioned between said illuminating means and said beam splitting member and comprising a confocal pair of focusing lenses together defining an optical axis and focusing said laser beam to a spot intermediate said lenses, a mask having a slit aperture situated at said focused spot, and averaging means disposed in front of said mask for continuously deflecting said spot in one direction only along the lengthwise direction of said slit, said mask and averaging means being coupled for rotation about said optical axis so as to orient said one direction optically perpendicular to said plane containing said axes of said first and second paths.