Direct laser writing of Fresnel microlenses with use of the scanning contour ablation method

Modern technological trends require the miniaturization of various devices, and hence the fabrication of micro-scale optical elements. Despite the existence of photolithography methods, which are commonly used for this purpose, there is still a need for developing fast prototyping solutions. In fact, the approach called ‘scanning contour ablation’, a direct laser writing-based method, has been developed for the fast reproducing of spherical micro-structures. In this paper, by introducing beam diameter as a variable and thus by updating the model, an improvement to the corresponding method is shown so that more complex structures like the Fresnel microlens can be reproduced. To confirm the assumptions, fabrication of exemplary microlenses was performed. The results of the study were characterized by a digital optical microscopy and compared to the given profiles.