Cотрудники института

Пикулин Александр Викторович
старший научный сотрудник


2005: ННГУ им. Н.И. Лобачевского, Радиофизический факультет, магистр радиофизики по направлению «Радиофизика»;
2005 – 2008: аспирантура в ИПФ РАН;
2008: ИПФ РАН, защита диссертации кандидата физико-математических наук по специальности 01.04.21 «Лазерная физика», тема диссертации «Нелокальные эффекты при лазерной нанополимеризации», научный руководитель Битюрин Н.М.

Область научных интересов:
Лазерная наномодификация полимеров, многофотонная полимеризация, ближнепольная лазерная литография, нанооптика, FDTD.

Профессиональная карьера:
2013 – настоящее время: старший научный сотрудник ИПФ РАН.
2010 – 2013: научный сотрудник ИПФ РАН;
2005 – 2010: младший научный сотрудник ИПФ РАН;
2003 – 2005: старший лаборант-исследователь Института прикладной физики РАН.

Научные визиты:
2009: Ганноверский Лазерный Центр (Laser Zentrum Hannover), Германия;
2005, 2006, 2007, 2009: Институт прикладной физики Университета Иоганна Кеплера (Institut für Angewandte Physik, Johannes-Kepler-Universität), г. Линц, Австрия;

Награды, премии, гранты:
2012 – 2013: руководитель гранта РФФИ  (мол_а) «Моделирование полимерных наносистем для задач фотоники»;
2011 – 2013: руководитель работ по ГК с Минобрнауки РФ (ФЦП «Научные и научно-педагогические кадры инновационной России» на 2009-2013 гг., мероприятие 1.3.1) «Наноструктурирование поверхности полимеров с помощью лазерной наносферной литографии»;
2007: стипендия им. академика Г.А. Разуваева;
2005: стипендия им. академика Ю.Б. Харитона.

Педагогическая деятельность:
Научное руководство студентами.

Количество публикаций:

Наиболее значительные работы и результаты:

1. N. Bityurin, A. Afanasiev, V. Bredikhin, A. Alexandrov, N. Agareva, A. Pikulin, I. Ilyakov, B. Shishkin, and R. Akhmedzhanov, "Colloidal particle lens arrays-assisted nano-patterning by harmonics of a femtosecond laser," Opt. Express 21, 21485–21490 (2013).
We consider nanopatterning of dielectric substrates by harmonics of single powerful femtosecond pulses from a Ti:Sapphire laser. The nanopatterning is mediated by closely packed monolayers of polystyrene microspheres that act as microlenses at the surface. Observed modification of the material proceeds via ionization. By our theory, the second harmonic is more effective in multi-photon ionization and is better focused than the fundamental frequency which is effective in multiplying of the amount of free electrons via impact ionization. Experiments show that conversion of a part of the pulse energy into the second harmonic decreases the modification threshold and improves the localization of the structures. Optimization of the time offset between the harmonics could further improve the efficiency and quality of nanostructuring.

2. G. Bickauskaite, M. Manousidaki, K. Terzaki, E. Kambouraki, I. Sakellari, N. Vasilantonakis, D. Gray, C. M. Soukoulis, C. Fotakis, M. Vamvakaki, M. Kafesaki, M. Farsari, A. Pikulin, and N. Bityurin, "3D Photonic Nanostructures via Diffusion-Assisted Direct fs Laser Writing," Adv. Optoelectron. 2012, 927931 (2012).

3. N. Bityurin, A. Alexandrov, A. Afanasiev, N. Agareva, A. Pikulin, N. Sapogova, L. Soustov, E. Salomatina, E. Gorshkova, N. Tsverova, and L. Smirnova, "Photoinduced nanocomposites—creation, modification, linear and nonlinear optical properties," Appl. Phys. A 112, 135–138 (2012).

4. A. Pikulin, A. Afanasiev, N. Agareva, A. Alexandrov, V. Bredikhin, and N. Bityurin, "Effects of spherical mode coupling on near-field focusing by clusters of dielectric microspheres.," Opt. Express 20, 9052–9057 (2012).
Colloidal particle lens array (CPLA) proved to be an efficient near-field focusing device for laser nanoprocessing of materials. Within CPLA, spherical particles do not act as independent microlenses. Due to the coupling of the spherical modes, the field near the clusters of spherical microparticles cannot be calculated by means of the superposition of Mie solutions for individual spheres. In the paper, the electromagnetic field distributions near laser-irradiated clusters of dielectric microspheres with configurations that match the fragments of the close-packed CPLA are studied. It is shown that some practically important mode coupling effects can be understood in terms of an effective immersion medium formed for the spherical particle by its surrounding.

5. А. В. Пикулин, Н. М. Битюрин, "Флуктуационные ограничения минимального размера вокселя при лазерной нанополимеризации", Журнал Технической Физики 82, 120–128 (2012).

6. I. Sakellari, E. Kabouraki, D. Gray, V. Purlys, C. Fotakis, A. Pikulin, N. Bityurin, M. Vamvakaki, and M. Farsari, "Diffusion-Assisted High-Resolution Direct Femtosecond Laser Writing," ACS Nano 6, 2302–2311 (2012).
We present a new method for increasing the resolution of direct femtosecond laser writing by multiphoton polymerization, based on quencher diffusion. This method relies on the combination of a mobile quenching molecule with a slow laser scanning speed, allowing the diffusion of the quencher in the scanned area and the depletion of the multiphoton-generated radicals. The material we use is an organic?inorganic hybrid, while the quencher is a photopolymerizable amine-based monomer which is bound on the polymer backbone upon fabrication of the structures. We use this method to fabricate woodpile structures with a 400 nm intralayer period. This is comparable to the results produced by direct laser writing based on stimulated-emission-depletion microscopy, the method considered today as state-of- the-art in 3D structure fabrication. We optically characterize these woodpiles to show that they exhibit well-ordered diffraction patterns and stopgaps down to near-infrared wave- lengths. Finally, we model the quencher diffusion, and we show that radical inhibition is responsible for the increased resolution.

7. A. Pikulin and N. Bityurin, "Spatial confinement of percolation: Monte Carlo modeling and nanoscale laser polymerization," Phys. Rev. B 82, 085406–9 (2010).

Modern laser nanoprocessing technology employs the sharp, thresholdlike response of modified materials to laser exposure to create nanofeatures with sizes that are smaller than the diffraction limit. In this paper, the percolation transition is examined as a possible physical mechanism that allows such a nonlinear spatial confinement of the laser material alteration. In particular, the percolationlike transition is involved in laser polymerization techniques, including two-photon polymerization, which is capable of producing three- dimensional nanostructures with sizes of 100 nm and smaller. We perform Monte Carlo modeling of percola- tion with the spherically symmetric occupation probability distribution that is constrained in three dimensions. The dramatic increase in the fluctuations of the size and position of the largest connected cluster is observed when attempting to decrease its size below the critical scale. For laser polymerization, this provides the natural fluctuation-managed limitation of the minimal size of a nanofeature. We present a model that allows the analytical estimation of the critical size of the largest cluster. This analytical model fits well with the data obtained from the numerical experiments.

8. A. Pikulin and N. Bityurin, "Spatial resolution in polymerization of sample features at nanoscale," Phys. Rev. B 75, 195430–11 (2007).
Recent developments in laser nanotechnologies allow overcoming optical limitations at the 100 nm level of spatial resolution. However, at such distances spatial restrictions on nanostructuring can be imposed by non- local response of the media. In the present paper, we consider nanostructuring by means of locally initiated radical polymerization of multifunctional monomers. Such local initiation can be provided, for instance, by femtosecond laser techniques. We theoretically analyze the limitations imposed by diffusion on the formation of two separate nanofeatures such as voxels, rods, and plates. Owing to the percolationlike transition occurring during the polymerization process, mathematical criteria for possible separation of such features are formu- lated.We develop a theoretical approach by consecutively taking into account diffusion of radicals of growing length. This approach allows us to estimate a characteristic spatial scale which determines the spatial resolution for the particular polymerizing system. For several realistic polymerizable resins, this resolution limit was estimated.

9. A. Pikulin, N. Bityurin, G. Langer, D. Brodoceanu, and D. Bäuerle, "Hexagonal structures on metal-coated two-dimensional microlens arrays," Appl. Phys. Lett. 91, 191106 (2007).
Hexagonally shaped apertures on metal-coated colloidal lattices of microspheres have been observed within certain parameter regimes of femtosecond Ti:sapphire-laser irradiation. The occurrence of such structures is explained by electromagnetic field interferences caused by the array of microspheres. The calculations are based on the splitting of the incident laser field into narrow paraxial Gaussian beams and their subsequent tracing and summation.

10. N. Bityurin, A. Pikulin, and A. Alexandrov, "Modeling of bleaching wave regime of UV laser polymerization of acrylates without initiators," Appl. Surf. Sci. 208-209, 481–485 (2003).