Originated from one of the research group of Crystals Physics Department the Nonlinear Optics Department (NOD) was established in 1965 to lead the research in the emerging branch of optics that describes the behavior of light in media with the dielectric polarization nonlinearly responded to the electric field of the light.

• nonlinear optics and spectroscopy of semiconductors (SC),organic polymers (OP) and nanostructures based on SC, OP and metals;
• crystal optics and physics of excitons.

Basic directions of scientific activity: nonlinear optical properties of condensed matter (semiconductors, polymeric materials, low-dimensional structures based on semiconductors and noble metals); dynamic holography and photorefractive effect study under pulsed laser excitation; research of A2B6- based quantum dot structures; properties of excitons and other quasiparticles in bulk and low-dimensional semiconductors.

Main facilities and experimental methods: measurements of nonlinear susceptibilities: nonlinear lens, four-wave mixing, Z-scan, pump and probe; methods of low- and high-temperature optical spectroscopy with spatial resolution under pulsed and stationary excitation of low dimensional systems; spectroscopy in the ultraviolet and IR spectral range; studies of indicatrices of optical scattering in the visual and IR spectral range.

• 1969 year – for the first time new optical nonlinear effect – self-bending – has been experimentally observed in alkali-haloid crystals and semiconductors
• 1965 – 2003 years – a fundamentals of the optics and spectroscopy of nonmetallic crystals in the exciton range with account of the polariton effects and of the influence of the surface and of the sample thickness have been established. A fundamental series of precise measurements which experimentally confirm the existence of additional light waves predicted by Pekar‘s theory in the case of the substantial spatial dispersion of dielectric permittivity has been carried out.
• The phenomena of exciton-exciton interaction at high levels of optical excitation have been investigated (biexcitons, electron-hole liquid, electron-hole plasma).
• 1967 – 1990 years – nonlinear crystal optics of semiconductors has been developed: two-photon spectroscopy, dynamic holography, light beam self-action effects, cavity less optical bistability, optical phase conjugation.
• 1986-1988 years – discovery of self-organization phenomena in the nonequilibrium, electron-hole system of semiconductors at high level of optical excitation: the first experimental observations for time-periodic oscillation of both density and temperature of gas phase around drops of electron-hole liquid in AgBr.
• 1995 – 2003 years – new highly effective optical nonlinear materials based upon epoxy polymers with covalently attached azo molecules have been discovered and studied, the origin of their optical nonlinearity being found out.
• 1998 – 2003 years – fast photo-refractive response (nano-second time range) with high gain coefficient (?=0,3 – 0,8 cm-1) has been studied in CdTe crystal doped with transition group metals - Ti, Fe, Ge, Sn.
• 2002-2008 years – quantum and dielectric contributions into both the exciton emission and their percolation transition in nanoclusters and quantum wells based on Zn(Se, S, Te) and Cd(S,Se) have been obtained.
• 2000 – 2008 years - a series of spectral and nonlinear optical studies of nano- composites based on TiO2 (anatase) and noble metals Au, Ag, Pd has been carried out. For the first time giant third order optical susceptibility has been obtained for both structure types: ?(3) ? 10-5 esu for TiO2 (?=1064nm) and 8,2·10-5 esu for Au (?=532nm). The nature of the giant nonlinear optical response has been studied.

Developments.

• Solid state lasers А2В6 semiconductors with laser generation tuned from visible to UV spectral range;
• nonlinear lenses with the focal length F depending on light intensity from ? to 1 cm and high speed of the focal length variation (10-8 - 10-12 sec);
• laser beam deflеctors with the scan angle до 5°;
• оptical bistable elements with the switching time and contrast up to 10-10 sec and ~5 respectively.

Awards

• Lenin Prize – 1966 year. (M.S. Brodyn).
• USSR State Prize - 1982 year. (M.S. Brodyn).
• Ukraine State Prize - 1974, 1981, 1983, 1994 year. (M.S. Brodyn, V.Ya. Reznichenko, А.О. Borshch, М.І. Strashnikova, N.O. Davydova, І.V. Blonskyy).
• Synelnikov prize - 1998 year. (M.S. Brodyn, S.V. Mаrіsоvа).
• Prykhot’ko prize – 2008 year. (V.I Volkov)

• New fundamentals of the optics and spectroscopy of nonmetal crystals in the excitonic spectral range taking into account polariton and spatial dispersion effects of dielectric permeability were built up (M. S. Brodyn, M. I. Strashnikova, S. V. Marisova, N. A. Davydova).
• Nonlinear crystallooptics of semiconductors, two-photon spectroscopy, dynamic holography, self-action of light beams, resonator less optical bistability, optical phase conjugation effects were developed (M. S. Brodyn, A. A. Borshch, V. Ya. Reznichenko, V. I. Volkov, S. G. Shevel).
• A series of spectroscopic and nonlinear optics studies of nanostructure materials based upon gold (Au), silicon carbide (SiC), and titanium dioxide (TiO2) have been carried out using nano-, pico-, and femtosecond laser radiation of different wavelengths. As a result, a giant third-order nonlinear susceptibility was observed for the first time for all above mentioned nanostructures: c(3) = 5,610–6 esu (SiC, l = 532 nm), c(3) = –8,210–5 esu (Au, l = 532 nm) and c(3) = (2–6)10–5 esu (ТіО2, anataz modification, l = 1064 nm). The nature of these nonlinearities was clarified (M. S. Brodyn, A. A. Borshch, V. I. Volkov, V. Ya. Gayvoronsky, V. R. Liakhovetskyi, V. I. Rudenko).
• A broadband optical limiter of nano-pico-femto-second laser radiation in the visible and near-infrared spectral range was manufactured using thin films of nanostructured SiC, which can work under extreme conditions of high and low temperatures, significant radiation exposure and chemically aggressive atmosphere (M. S. Brodyn, A. A. Borshch, V. I. Volkov, V. I. Rudenko).
• In the KDP crystals incorporated by TiO2 nanoparticles, a 1.5–2-fold increase of the efficiency of second-harmonic generation in comparison with the nominally clean KDP crystal was obtained for the first time. The effect is due to the resonant excitation of nanoparticle defect states and the proton subsystem reconstruction beside the nanoparticles resulting in the self focusing of a pump laser beam (V. Ya. Gayvoronsky, M. S. Brodyn, M. A. Kopylovsky).
• On the basis of the quantum percolation model, the nature of exciton phase percolation transitions in a low-dense quantum-dot array of II–VI semiconductors with different sizes and topology. Factors that influence the exciton energy and the optical properties of quantum objects, as well as their dependence on the object size (charge carrier moving quantization, dielectric contribution and surface states), were determined (M. S. Brodyn, M. V. Bondar).

Effect of broadband optical limiting
in a nanostructured SiC film of nanosecond laser radiation in the visible and near-infrared range
(the the electronic photo of the SiC film structure is shown in the left panel)

• М.S. Brodyn, E.N. Myasnikov, S.V. Mаrisоvа. "Pоlaritons in crystal optics”, Kiev, Naukova dumka, 1984 (in Russian).
• М.S. Brоdin, I.V. Blоnskyy. "Excitоn prоcеsses in layered crystаls". Кiеv, Naukova dumka, 1986 (in Russian).
• A.Borshch, M.Brodin, and V.Volkov. "Refractive nonlinearity of wide-band semiconductors and applications". London: Harwood Academic Publisher, 1990.
• М.S. Brоdyn, I.V. Blоnsкyy, B.М. Nitsovich, V.М. Nitsоvich. "Dynamical processes in the multi-component gas of quasi-particles". Кiеv, Nаuкоvа dumka, 1990 (in Russian).
• М.S.Brоdyn «Advanced рhotorefractive materials », моnоgrаphic collectоr «Advanced маtеriаls and tеchnоlоgies», Кiev, 2003, v.2, р.351-373 (in Russian).
• М.І.Strashnikova “Influence of Pekar additional light waves on optical spectra of crystals” (review), Ukr. J. Phys. 52, №8, 754-785, 2007.
• A.O.Bоrshch , М.S Brоdyn , V.Ya Rеznіchenko , K.V. Shchеrbin «Studіes of nonlіnear оptics of semiconductors in the Іnstitute of Physics of the National Academy of Sciences of Ukraine», in book “Institute of Physics NASU.80 years “ Lviv, Eurosvіt, 2009 (in Ukrainian).

International scientific cooperation: Germany (Universities: Marburg, Karlsruhe, Jena), Russia (M.V.Lomonosov Moscow State University , P.N. Lebedev Physical Institute of the Russian Academy of Sciences), Great Britain (Manchester University), Poland (Wroclaw, Institute of Low Temperature and Structure Research), Greece (National Technical University of Athens)

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  Working time at laser system "Neodymium": V.I. Volkov, V.R. Lyahovetskyy and A.A. Borsch.

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  The workshop department. M.S.Brodyn, NA Davydov, Mikhail V. Bondar.

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  Discussion of research plans.

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  M.S. Brodin and V.J. Hayvorons'kyy young employees observe
  effects samovplyvu laser radiation in nanocomposite materials.

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  The department nonlinear optics in 1990.

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  Collective photo of department

• Studies of nonlinear optical and spectral properties of nano-dimensional systems (state registration No. 0108U000089).
• Investigation of optical and nonlinear optical properties of nanostructures based on noble metals and semiconductors: development of new high sensitive techniques for studying and testing nanostructures (state registration No. 0110U004585).
• New nonlinear optical heterogenic materials based on a dielectric matrix incorporated by metal oxides nanocrystals for photonics (state registration No. 0109U007531).
• Nonlinear optical response of liquid crystals doped with organic dyes (CRDF # UK-P1-2617-KV-04).

Website of nonlinear optics