Computer-drawn modulated zone plates.

The structure of Fresnel zone plates is considered as a binary carrier of complex modulation functions. Due to the Fourier-transforming roperties of this particular carrier, any original object can be reconstructed with a simple monochromatic point source using no additional optics. An analysis of modulated zone plates (MZP) verifying their Fourier-transforming and imaging properties is given. experiments were performed with several types of computer-drawn MZP's. Results illustrating the flexibility of this method are in good agreement with theory. The simple method of reconstructing and scaling the object intensity distribution, the high efficiency, as well as he resistance against high laser intensities show the MZP to be a convenient tool for laser micromachining of patterns with optional shape.