LENSACON

A diffractive optical element has been synthesized with laser phototec hnology. It can transform a point source into a bright caustic (a ligh t Line) stretched along the optical axis. The element transforms a sph erical wave into a conic and a point source in the object space to a r ing structure in the image space. We investigated how the parameters o f the light line (the length and the effective diameter) depend on the wavelength of the light source and the movement of the source along t he optical axis. Also the interference field outside the caustic (Fres nel and Poisson fringes) was investigated. For an explanation of exper imental data the geometrical theory of interferometers was used. The c onditions for the appearance of fringes in white light are given. A de vice for rectilinear control of large tool beds and for centering mach ine components was manufactured. Experiments on determining the macros hape and the microshape of objects were performed.