In this paper we propose a one step marking process using a high power near infrared fiber laser and diffractive optical elements or gratings as an alternative to traditional scanning systems. The impact of the gratings fill factor, the power level on the diffracted beams and the quality of the reconstructed images are studied. We present simulation results of gratings diffraction efficiencies, experimental observations of gratings and DOEs behaviour illuminated with a fiber laser beam. We demonstrate that the fiber laser, showing good beam quality, can be used with standard diffractive structures with interesting results.
We have prepared an organic/inorganic hybrid using sol-gel process. The material exhibits thermal, mechanical and optical properties well adapted to the patterning by laser micromachining. We have achieved the fabrication of optical elements by this mean validating the process at micrometric scale. Optical waveguides have been fabricated in 3-4 micrometer thick hybrid sol-gel films deposited by spin coating on borosilicate glass substrates. Here laser ablation is used to remove matter on both sides of the waveguide core. The laser micromachining of hybrid sol-gel is also adapted to the fabrication of multilevel diffractive optical elements. Indeed, the ablation depth can be precisely controlled by the fluence of the laser and/or the number of pulses. This study demonstrates that laser micromachining of hybrid sol-gels permits the fast fabrication of effective optical devices, making this process well adapted to rapid prototyping or fabrication of masters.