Nanostructured kinoform optical elements for high power laser systems

Different kinoform elements have been fabricated in fused silica by precise chemical etching. Kinoform phase relief have been made with an accuracy of ~5 nm. A vortex kinoform mode converter which transforms a zero order Hermite-Gaussian laser mode to first order Laguerre-Gaussian mode with screw phase dislocation has been demonstrated. Conversion efficiency >90% for high power laser beams has been achieved in testing experiments.