Laser lithography

The commercial lithographic system situated in class 100 cleanroom at IPHT Jena, was used for the writing of more sophisticated diffractive elements such as planar and cylindrical lenses, crossed gratings, waveguides and artificial holograms. It employs the He-Cd laser operating at a wavelength of 441.0 nm. Its writing speed was approximately 100 mm/s, and the dose used was in the range of 17-80 mJ/cm$^2$. Laser focusing system uses an air stream and is capable of focus the beam down to a size of 700-800 nm in diameter. The writing system is comprised of the laser objective, which is fixed, and a base table with the substrate(s), which is movable.