Improvement of Thermochemical Processes of Laser-Matter Interaction and Optical Systems for Wavefront Shaping

Abstract

Laser thermochemical processes of metal surface oxidation are promising for creating new advanced technologies to meet the growing needs of opto- and micro-electronics, photonics, catalysis, sensorics and other high-tech industries. The features of thermochemical processes of laser-matter interaction occurring in matter under exposure to intense light flows and optical systems for controlling the irradiance and wavefront spatial distribution were reviewed. The laser beam offers the possibility of good focusing, which allows us to conduct chemical reactions, including the heterogeneous oxidation of metals, locally, with high spatial resolution. In this case, the absorption mechanisms of the laser beam vary for metals and for oxides, resulting from a thermochemical reaction and represent semiconductors. For semiconductors, the intrinsic, intraband, impurity, or lattice absorption takes place. The morphology of a metal surface also influences its optical absorption capacity. The improvement of beam shaping systems with elements of computer optics, namely diffractive freeform optics, provides an opportunity for an efficient control of chemical processes by achieving the desired redistribution of the laser beam power density. Laser thermochemical processes of the formation of quasi-one-dimensional nanostructured metal oxides are of great interest for advanced research and for a wide range of applications. A special feature of these processes is that, in the case of a frequency-modulated laser beam the synergy between the heat associated effects of the laser pulses and the laser-induced vibrations allows for a significant increase in the diffusion coefficient, which is stimulated by the non-stationary stress-strain state of the material. Ensuring the means of control over the thermochemical reaction in local sections of the laser exposure zone is an issue that can be solved by adapting the shape of the laser beam by the diffractive freeform optics. The gained knowledge contributes as a foundation for new photonic technologies oriented on the formation of nanostructured metal oxides, involving control over the morphology of the synthesized structures.

Creation of One- and Two-Dimensional Copper and Zinc Oxides Semiconductor Structures

“…The outlined approach opens up new possibilities for creating oxide nanostructures that have applications in various fields such as optoelectronics, sensorics, the manufacturing of electronic devices and portable energy sources, and many others. The use of free-form diffractive optics [153] within the optical system for precisely focusing the laser beam into a predefined area of the material's surface enables the effective control of heating and oxidation processes [26,34].…”

“…To develop innovative advanced technologies that meet the growing needs of hightech sectors, promising laser-thermochemical processes for oxidizing metal surfaces are being actively researched [26]. These developments are important for creating more efficient and sustainable devices; for example, the laser-induced thermochemical recording of microand nano-dimensional structures is gaining attention for its applications in photonics, particularly in the production of optical transducers [27][28][29].…”

Dynamic freeform diffractive lens

“…Starting from an input laser beam with known optical features the shaping should be able to generate an output laser illumination with prescribed characteristics. Hence, beam shaping can be though as a solution of an inverse problem (IP) that determines the proper optical surfaces to get desired illumination [2,6]. For many laser applications, having user-defined intensity distributions may be sufficient to achieve the expected results.…”

Investigation of Non-Metallic Material Laser Processing Modes

“…Широкое распространение в промышленности при обработке различных поверхностей получили лазеры и лазерные технологии. Уникальные физические свойства лазерного излучения способствуют расширению применения лазерных технологий при изготовлении художественно-промышленных изделий [10][11][12]. Однако лазерная обработка применяется недостаточно широко; порой разработчикам не удается реализовать замысел, предусмотренный проектом, в связи с недостаточной изученностью возможностей лазерных технологий и отсутствием рекомендаций для их применения [13].…”