Microprinting and microetching of diffractive structures using ultrashort laser pulses

Two complementary methods, the microetching and the microdeposition, of materials using ultrashort pulses of ultraviolet (UV) laser radiation for the fabrication of diffractive structures are presented. Microetching of various solid materials (polymers, metals) using femtosecond excimer lasers produces high definition micron diffractive patterns. The microdeposition method utilizes the selective microablation and transfer of thin metallic films for achieving microstructures of dots, lines and complicated multilevel patterns with micron and even submicron resolution. The short pulse length and the consequent limited thermal diffusion, lowers the ablation threshold and enables the machining and the deposition of high definition features. The superior quality of the results allows the direct, in-one-step process, fabrication of binary amplitude and multilevel optical diffractive structures on planar and cylindrical substrates such as optical fibres. (C) 1999 Elsevier Science B.V. Ail rights reserved.