Laser Technologies for Micro- and Nanoprocessing of Glass
Glass is a material, which can be applied to different fields. It is used to make simple test tubes and also complex microanalytical systems and integrated optical circuits. Processing of glass at a microscopic level is a challenging task. Here is how scientists at the Department of Laser Systems and Technologies solve these problems.
Products made of glass became popular due to development of the architecture of macro objects when the era of skyscrapers started. Later such tendencies inspired engineers and researchers to create complicated and unique micro systems.
A disadvantage of these micro systems is that using them it is easy to study various super microscopic physical-chemical processes. Such micro systems are easily detected and measured by the equipment like optical devices or supplying and deflecting ones. In these terms, fused quartz is the most appropriate material, as it is transparent and has high chemical, thermal, electric and biological resistance. However due to the same reasons micro processing of glass is still very challenging — its realization needs many steps, producing such micro systems requires much time. Scientists at ITMO’s International Research Laboratory "Laser Micro and Nanotechnologies" explored prospects of laser-induced micro and nanoprocessing of glass.
According to Maksim Sergeev, researcher at the Department of Laser Systems and Technologies, using mechanical methods of micro and nanoprocessing it is difficult to develop high-resolution systems of high quality. Furthermore, these methods don’t allow creating local structures that are smaller than a micrometer and have diversified depth. Unlike mechanical methods, laser technologies help provide contactless processing of super small glass objects.
"One pays a great attention to µ-total analytical systems including lab-on-a-chips that are produced in the whole world. However glass processing is a high-tech and complex process. This makes developing of less expensive technologies very relevant, as they help shorten the process of producing such micro systems and also reduce their cost," explains Sergei Maksimov.
The researcher and his colleague, engineer Roman Zakoldaev, solve these problems by developing methods of laser microprocessing of glass and glass ceramic materials. Using laser radiation one can record required structure in glass and then with the assistance of thermal and chemical processing one creates a required detail.
"Managing space-time characteristics of a laser and features of a material one can develop a modified structure with unique peculiarities. These modified areas with spectral-optical and plasmonic features serve as functional elements of a microsystem," adds Roman Zakoldaev.
The next step of producing functional elements of microsystem devices is making nanoscale structures of composite materials on the base of silicate glass with nanoparticles that have different features. Laser-induced production of such structures is a difficult task. One can solve it by combining physical fundamentals of interaction of laser radiation and materials with chemical-technological processes of its producing.
The results of this research were presented at international scientific conferences. For instance, a report on structural modification of porous glass by ultra-short laser pulses was called the best at the 17th International Symposium on Laser Precision Microfabrication which took place in China in May 2016. Another report by the Russian researchers devoted to the application of laser induced microplasma to transparent dielectrics structuring was also announced as one of the best works at a report contest, which was part of the Advanced Laser Technologies International Conference.
V. P. Veiko, S. I. Kudryashov, M. M. Sergeev, R. A. Zakoldaev, P. A. Danilov, A. A. Ionin, T. V. Antropova, I. N. Anfimova, Femtosecond laser-induced stress-free ultra-densification inside porous glass, Laser Physics Letters, April 1, 2016.
G. K. Kostyuk, R. A. Zakoldaev, M. M. Sergeev, E. B. Yakovlev, Microlens array fabrication on fused silica influenced by NIR laser, Applied Physics B, April 12, 2016.