Fabrication of submicron gratings in fused silica by F2-laser ablation

Submicron surface-relief gratings were fabricated on fused silica by F-2-laser ablation with nanosecond duration pulses from a high-resolution 157-nm optical processing system. A 157 nm wavelength projection mask was prepared by ArF-laser ablation to form a 20-mum period grating of equal lines and spaces. A 25-fold demagnification of the mask by a Schwarzschild objective generated gratings of an 830-nm period and a 250 nm modulation depth, as characterized by SEM, AFM and HeNe-laser beam diffraction.