A precision laser pattern generator for writing arbitrary diffractive elements was developed as an alternative to Cartesian coordinate laser/electron-beam writers. This system allows for the fabrication of concentric continuous-relief and arbitrary binary patterns with minimum feature sizes of less than 0.6 microm and position accuracy of 0.1 microm over 300-mm substrates. Two resistless technologies of writing on chromium and on amorphous silicon films were developed and implemented. We investigated limit characteristics by writing special test structures. A 58-mm f/1.1 zone plate written directly is demonstrated at a lambda/50 rms wave-front error corresponding to a 0.06-microm pattern accuracy. Several examples of fabricated diffractive elements are presented.

Local laser oxidation of thin metal films allows recording of an optical image on thin films with the highest resolution and high productivity at the same time, and without distortions specific to laser ablation. A technique for writing of diffractive optical elements was developed on the basis of this process. Laser-matter interaction physics and laser technology underlying this method are described in this chapter. IntroductionIn our opinion, laser oxidation of thin metal films is a successful example of the discovery of a new effect, its explanation and application. Furthermore, although all these developments took place at the beginning of the laser era, the interest in these has not decayed up to now, not to mention a new technique (short-pulse laser writing), at this point, a new physics was also required due to the coming of the "nano" era.Let us briefly describe these developments in the introduction because the authors were their direct participants. The effect that formed the basis of the research field under discussion was first observed in our experiments aimed to determine the evaporation thresholds q ev of thin chromium films exposed in the optical projection

Fizeau interferometers with an additional diffractive optical element are frequently used for measuring spherical and aspherical surfaces. We present a new (to our knowledge) optical test method, in which the Fizeau principle is now perfectly fulfilled by generating reference and measuring wavefront on the last optical surface, which carries a diffractive optical element. This method has been examined experimentally by testing a reference f/0.68 spherical mirror and can be applied identically for testing aspheres. Several advantages of this method are discussed and proved experimentally.

A novel type of a combined (or multiplex) computer-generated hologram (CGH) and a method for interferometric testing of steep axially symmetric aspheres is presented. The method is based on a hybrid CGH containing two different diffractive structures. The presented new type of Diffractive Fizeau Null Lens (DFNL) design eliminates the transmitted wavefront distortion (TWD) of the CGH substrate and increases the accuracy of the surface test. The method was approved by testing a spherical reference mirror with an f-number of f/0.65.