A high resolution, holographically corrected microscope with a Fresnel lens objective at large working distances

We present details of a microscope which incorporates an inexpensive, high numerical aperture Fresnel lens objective. The system aberrations are corrected by the use of an image hologram of the lens recorded using a point source of coherent illumination. This device gives high resolution, real time imaging while maintaining a large working distance. The same microscope can be used for micromachining and photolithography in situations where close proximity to the sample is impossible or undesirable.