CC BY
5The 30th International Conference on Advanced Laser Technologies LM-I-20
ALT'23
precision laser technologies for optical instrumentation
V. Bessmetlsev, V. Korolkov, A. Dostovalov, S.A. Babin
IA&E SB RAS, Koptyuga ave.1, 630090, Novosibirsk, Russia
Main author email address: [email protected]
The development of new laser technologies and equipment for its implementation is aimed not only at increasing the resolution and productivity of the micro-/nano-processing, but also at increasing an accuracy, including both spatial localization and compliance with a given degree of transformation of the processed material, given parameters. Over the past decades, the IA&E SB RAS has been developing areas of applied research related to the fundamental and engineering foundations of precision laser technologies focused on the problems of optical instrumentation. To improve the quality and speed characteristics, a complementary scanning principle is used, in which a fast galvanoscanner with a short-focus lens and a small recording field is used to obtain a high scanning speed and a minimum point in focus, and a full recording field is obtained due to the precise movement of the microprocessing object and software-hardware docking fields.
The advent of pico- and femtosecond lasers with a high average power caused a sharp surge in research on the micromachining of various materials, including brittle ones, providing a new quality of processing. However, when trying to increase the productivity of processing at micron and more depths of micromachining by increasing the energy per pulse or the number of pulses in a pack, the resulting thermal and hydrodynamic effects significantly worsen roprocessing object and software-hardware docking fields.
For processing fragile materials, such as glass, quartz, semiconductor materials, raster scanning technologies have been developed within the contour of the zone of the removed material, which take into account the length of the processing line, the overlap of focused spots and the pulse energy. When forming deep microchannels to obtain high-quality walls, the direction of microchannel processing is taken into account. The technology used has made it possible to increase the productivity of micromachining of brittle materials by several times and improve the quality of processing. the quality of processing materials with low thermal conductivity and a tendency to form microcracks. The technology of femtosecond laser modification of transparent materials makes it possible to perform precision surface micromachining of the surface of various optical elements, for example, to increase the transmission of nonlinear optical crystals with a high refractive index and high optical losses due to Fresnel reflection. We present the results on the development of antireflection microstructures on the surface of a GaSe crystal, demonstrating an increase in transmission from 65% to 80% in case of fs laser inscription of microstructures on one side and up to 94% in case of micromachining on both sides. Based on the surface profile of a single crater measured by atomic force microscopy, the transmission spectra for GaSe with the microstructures are numerically calculated that is in a good agreement with the experimental data.
The report also considered a technological complex created for piece and small-scale production of diffractive and micro-optical elements based on laser technologies in combination with vacuum-plasma technologies and optical methods of product control. The complex includes a system for magnetron sputtering of thin films, a circular laser system [1] for resistless thermochemical writing of microstructures on chromium films [2], an X-Y system [3] for laser lithography on a photoresist, reactive ion etching systems, optical profilometers and diffractometers. The experience of using this equipment for the manufacture of microstructured optical elements of various types is discussed. The equipment of the Central Research Center "Spectroscopy and Optics" of the IA&E SB RAS and Core Facilities VTAN NSU were used in the research. The work was supported by the Russian Science Foundation grant (No. 21 -7220162).
[1] A.G. Poleshchuk, VP. Korolkov, V.V Cherkashin, S. Reichelt, and J. Burge "Polar-coordinate laser writing systems: error analysis of fabricated DOEs", Proc. SPIE 4440, pp. 161-172 (2001).
[2] V.P. Veiko, V.P. Korolkov, A.G. Poleshchuk, D.A. Sinev, E.A. Shakhno, Laser technologies in micro-optics. Part 1. Fabrication of diffractive optical elements and photo-masks with amplitude transmission, Optoelectronics, Instrumentation and Data Processing, vol. 53(5), pp. 474-483 (2017).
[3] https://heidelberg-instruments.com/product/dwl-66-laser-lithography-system/
