Fabrication and evaluation of a diamond diffractive fan-out element for high power lasers

Fabrication and evaluation of diamond binary diffractive fan-out elements is demonstrated. The diffractive optical elements (DOEs) are designed for two different wavelengths, 633 nm and 10.6 μm. The DOE splits an incident beam into 16 spots that form a ring pattern. The surface reliefs were fabricated by photolithographic methods followed by plasma etching, which produced well-defined patterns with smooth surfaces. One DOE was optically evaluated with a HeNe laser, operating at a wavelength of 633 nm, and showed good performance. The DOE designed for a wavelength at 10.6 μm was tested together with a carbon dioxide laser. The light pattern was used to microstructure a 10 mm thick PMMA piece with very good results.