PARTIALLY COHERENT OPTICAL SYSTEM WITH SCATTERING TYPE OBJECT

An optical system having a projection lens for imaging a scattering type thermo optic cell on an image receiving surface, comprising optical source apparatus for generating an optical beam and an image created on the scattering type thermo optic cell having a minimum feature size, the optical beam propagating through the object on the scattering type thermo optic cell. Also provided is a condenser system which illuminates the scattering cell and underfills the aperture of the projection lens, thereby creating a partially coherent imaging system. As a result, a relatively higher contrast ratio for the minimum features of the image is obtained at the image receiving surface.