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  • Alexander I. Ignatiev
Alexander I. Ignatiev

Alexander I. Ignatiev
ITMO University | SPbNRU ITMO · Department of Photonics and Optical Information Technology

About

88
Publications
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757
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November 2003 - present
ITMO University
Position
  • Principal Investigator

Publications

Publications (88)
Article
Full-text available
The well-known standard photo-thermo-refractive (PTR) glass has some limitations in holographic applications in the visible region due to light scattering on the large NaF nanocrystals formed during the photo-thermo-induced (PTI) crystallization process. The large size of the NaF nanocrystals can be reduced by forming more nucleation centers (silve...
Article
Full-text available
In this work bromide photo-thermo-refractive glasses with different Ytterbium concentration were explored. It is shown that UV irradiation and subsequent heat treatment of samples with Yb 2 mol.% causes significant red-shift absorption line from 410 nm with temperature lower than T g to 517 nm with temperature T g +60 °C. For small concentration of...
Article
Full-text available
A series of lithium-germanate glasses with different manganese concentration is synthesized. Li 2 Ge 7 O 15 nanocrystals nucleate in the glass matrix via standard volume crystallization technique thus obtaining lithium-germanate glass-ceramics. The glass-ceramics possess intense emission near 660-670 nm under two-band excitation at 330 and 450 nm....
Article
Pure CsPbBr3 and CsPbI3 perovskite nanocrystals are nucleated in the borogermanate glass. Nanocrystals precipitation in glass are controlled via isothermal treatment at temperatures above Tg by adjusting the temperature and duration starting from 15 min. X-ray diffraction data and optical measurements have confirmed the formation of 5-8 nm sized Cs...
Article
Full-text available
Gadolinium oxide nanopowders doped with neodymium were prepared via modified Pechini method based on double stabilization of nanoparticles. Polyvinylpyrrolidone was used as an additional stabilizer at low-temperature stage of synthesis. This polymer also acts as a fuel during thermal treatment of precursors. Photoluminescence and FTIR spectroscopy,...
Article
We developed a new chloride photo-thermo-refractive glass doped with ytterbium ions. The dependence of optical and spectral-luminescent characteristics on ytterbium concentration has been studied. Concentration dependence of excited state decay time has been analyzed taking into account the self-trapping and self-quenching mechanisms. The optimum c...
Article
In this study, the influence of small additives on the spectral and optical properties of Na+–Ag+ ion-exchanged silicate glass is presented. Polyvalent ions, for example, cerium and antimony, are shown to reduce silver ions to atomic state and promote the growth of photoluminescent silver molecular clusters and plasmonic silver nanoparticles. Na+–A...
Article
Full-text available
The paper describes aspects of Gd 2 O 3 :Nd ³⁺ phosphors synthesis by the liquid polymer-salt method. The double role of polyvinylpyrrolidone as an organic solvent was revealed in the process of highly-luminescent cubic nanocrystals formation. The developed technique was applied for modification of a hollow-core anti-resonant optical fiber by thin...
Article
Alkali-alumina-borate glass-ceramics co-doped with Cr and Sb ions are synthesized by the melt quenching technique. LiAl7B4O17 nanocrystals are formed in the glass host during the two-stage heat treatment at the crystallization temperature. For the samples of the initial and heat-treated glass with high antimony oxide content (>0.05 wt%), absorption...
Article
Spectral-luminescent characteristics of erbium ions in photo-thermo-refractive (PTR) glasses doped with different concentrations of ytterbium and erbium oxides were investigated in this work. X-ray diffraction pattern of studied glasses was carried out. Judd-Ofelt parameters of intensity Ωt were obtained and used for deriving emission cross-section...
Article
Phosphate glass with a high transmission level in the visible and near-IR spectral regions doped with a high cerium concentration (up to 25 mol%) was synthesized and experimentally investigated in terms of applicability as a material for magneto-optical devices. Glass transition temperature was 590 °C. Glass refractive index varied between 1.5831 a...
Article
Full-text available
Chromium-doped alkali alumina borate glass was synthesized. The DSC studies exhibited glass transition temperature to be 425°C and glass crystallization temperature to locate in the 600 – 700°C range. After isothermal treatment of glass samples at temperatures from 540 to 700°C the chromium-doped borate glass-ceramics was obtained. The two bands of...
Article
Alkali alumina-borate glass-ceramics doped with different concentration of Cr3+ ions was prepared by conventional melt-quenching technique. Luminescent glass-ceramics was derived by volume crystallization of the precursor glass via two-stage heat treatment. The phase transition temperatures, structure, spectral and luminescent properties of the gla...
Article
The results of complex action of X-ray and nanosecond UV laser radiation on alkali-containing silicate glasses are presented. It is shown that X-ray irradiation of glasses forms luminescent color centers in them, which is related to increasing concentration of structural defects in glass network. Laser radiation destroys these defects, which is acc...
Conference Paper
Full-text available
Laser and holographic properties of a new photo-thermo-refractive glass doped with neodymium and ytterbium-erbium ions have been studied. The glass is a promising medium for monolithic integration of laser and holographic elements.
Conference Paper
Ion exchange technique is well known for decades as a versatile tool for fabrication of optical waveguides in glass matrices. Photo-thermo-refractive (PTR) glass is a photosensitive medium used for Bragg gratings recording. PTR glass is a sodium-zinc-aluminosilicate one doped with cerium, antimony, silver, and bromine. In this work influence of the...
Chapter
Fluoride Photo-Thermo-Refractive (PTR) glasses are very promising materials for recording Bragg gratings for different laser applications. Design and fabrication of novel chloride and bromide PTR glasses will be discussed. It was shown that various technologies as photo-thermo-induced crystallization, holograms recording, laser treatment, ion excha...
Article
The effect of silver on the optical, spectral-luminescent, and crystallization properties of bromide photo-thermo-refractive glasses is studied. Multicomponent photosensitive glasses of the Na2O–ZnO–Al2O3–SiO2 system with photosensitizing agents (cerium, antimony, silver) and halogenides (fluorine and bromine) are synthesized. Ultraviolet irradiati...
Article
Full-text available
In the present research, a new class of bromine-containing photo-thermo-refractive (PTR) glass in which the UV irradiation and subsequent heat treatment cause the precipitation of silver nanoparticles with a shell consisting of silver bromides is developed and studied. The growth of AgBr nanocrystals is shown to lead to a local positive refractive...
Article
Dielectric constant spectra of photo-thermo-refractive (PTR) glasses with silver in temperature range of − 50 to + 250 °C and frequency range from 0.1 Hz up to 1 MHz are presented. Glasses without and with silver, after UV irradiation and heat treatments were under study. It is shown that doping of the glasses by a small amount of silver (0.124 mol...
Article
Photo-thermo-refractive glass is now promising material for developing various elements and devices of photonics. The effect of variations in the Sb2O3 concentration in the photo-thermo-refractive glass composition on the spectral-luminescent properties of silver clusters formed with the low-temperature ion exchange is studied for the first time. T...
Chapter
Full-text available
This chapter presents a survey of recent achievements of the ITMO University (St. Petersburg, Russia) in developing new holographic media such as fluoride, chloride, and bromide silicate photo-thermo-refractive (PTR) glasses as well as the holographic diffractive optical elements that are the volume Bragg gratings recorded in the glasses for improv...
Article
Experiments and numerical simulation show that the irradiation of alkali-containing glasses using electrons at an energy of 35 keV and the subsequent thermal processing at a temperature above the vitrification point lead to the formation of spherical metal (lithium, sodium, and potassium) nanoparticles with oxide sheaths that exhibit plasmon resona...
Article
The formation of silver molecular clusters and nanoparticles in photo-thermo-refractive (PTR) glasses with different antimony contents has been investigated using ion exchange with subsequent thermal treatment. The influence of the antimony oxide (Sb2O3) concentration and treatment temperature on the spectral-luminescent properties of silver molecu...
Article
Full-text available
Subject of Study.The paper deals with novel research of ion exchange duration influence on spectral-luminescent properties of silver clusters formed in photo-thermo-refractive glass. Method. Photo-thermo-refractive matrix glass based on Na2O–Al2O3–ZnO–SiO2–F (% mol.) system doped with 0,002% mol. of Sb2O3 was synthesized for further research. Silve...
Conference Paper
Quasi–CW laser action on heavily doped Nd:PTR glass with diode pump was demonstrated. It was shown that laser operates in single mode regime. Achieved slope efficiency was measured to be ~ 17%. Further analysis showed that PTR glass possess low round trip losses, even in comparison with commercially fabricated Nd:YAG crystals.
Article
Full-text available
We have carried out calculations of recording conditions for multiplexed holograms in photo-thermo-refractive (PTR) glass. The proposed calculation sets the link between such parameters as: the angle between recording beams and the angle of sample rotation, operating wavelength, the angle of incidence on the element, output angle. To study recordin...
Article
Full-text available
The spectral characteristics of a high-power semiconductor laser with an external cavity in which longitudinal-mode selection is implemented by means of a holographic volume Bragg grating recorded in photo-thermo-refractive glass are investigated. Mode selection leads to narrowing of the spectrum of the laser diode from an initial width of 6 nm to...
Article
The known photo-thermo-refractive (PTR) glass is a photosensitive multi-component silicate glass containing fluorine and bromine and doped with cerium, antimony, and silver. The UV irradiation and subsequent heat treatment of this glass result in the crystalline phase precipitation and negative refractive index change up to 1000 ppm in the UV-irrad...
Article
Photostructurable properties of photo-thermo-refractive glass are discovered for the first time. The etching kinetics in HF solutions for virgin photo-thermo-refractive glass and glass ceramics are investigated. The etching rate of the glass ceramics is shown to be more than ten times higher than that of glass. Future prospects of applying the chem...
Article
It is shown that glass fibers doped with luminescent molecular clusters of silver, cadmium and lead chalcogenides, or copper (I) can be used for the efficient radiation conversion of ultraviolet (UV) radiation to the visible spectral region. The advantages of radiation trapping in fibers by the luminescent centers and of spectral conversion are dis...
Article
The breakdown processes of silver nanoparticles in the volume of photothermorefractive glasses when they are irradiated with a femtosecond laser (800 nm, 120 fs) is investigated as a function of the dose and energy density of the radiation (0.012-4 J/cm(2)). It is shown that the amplitude of the plasmon-resonance absorption band of silver nanoparti...
Article
Photo-thermo-refractive (PTR) glasses are the class of polyfunctional materials that combine the properties of several monofunctional materials such as photo-refractive, laser, luminescent, and plasmonic ones. Based on PTR glasses, various diffractive holographic elements and photonic devices were developed in both the volume and fiber versions. In...
Article
It is experimentally shown that irradiation of silver-containing glasses by nanosecond laser pulses with a wavelength of 248 nm leads to the formation of unstable point defects (having absorption bands in the UV and visible spectral ranges) in the irradiated region and causes the transition of ions and charged molecular silver clusters to the neutr...
Article
Full-text available
It is shown experimentally that the result of the UV nanosecond laser irradiation of the silver-containing photo-thermo-refractive (PTR) glasses depends on the prehistory of glass. If the PTR glass was preliminary irradiated by the UV radiation by UV mercury lamp into the absorption band of Ce 3+ ions the laser irradiation results in the silver mol...
Article
Full-text available
The novel photo-thermo-refractive (PTR) glass developed in ITMO University is a very promising optical material for photonic and plasmonic applications. In this paper authors represent study of tin influence on photo thermo inducted crystallization process and make a comparison of the optical and holographic properties of the new and classic compos...
Article
Full-text available
It is experimentally shown that irradiation of silver-containing silicate glass by IR femtosecond laser pulses leads to generation of free electrons in glass as a result of multiphoton ionization. Free electrons, being captured by charged molecular silver clusters, transform them into the neutral state, as a result of which the luminescence intensi...
Article
Data accumulated on the UV spectra of photo-thermo-refractive glasses known to be a new class of photo-sensitive materials for nanophotonics is discussed. The paper is aimed to providing specialists in the applied photonics with a complete self-consistent block of the latest information on the UV spectral manifestations of various oxidation states...
Article
Full-text available
We compare spectral and holographic characteristics of a novel material designed for manufacture of photothermorefractive (PTR) glass. The parameters of holograms recorded in classical and modified PTR glass are confronted. It is shown that unlike the classical PTR glass, the modified PTR glass does not have an additional absorption band in the blu...
Article
This article discusses how x-irradiation affects the formation of silver clusters, based on spectroluminescent studies. Increasing the x-ray irradiation dose increases the optical density of the test glasses in the 300–450-nm region and causes an absorption band to appear in the 300-nm region in the case of glasses that contain Na+. Replacing Na+ w...
Article
Full-text available
Review on latest modification applied to chemical composition of PTR glass was made. Advancements of updated chemical composition of PTR glass was shown in comparison with commercially produced glass. Such properties as refractive index change, optimal exposition and optical losses in visible range for the glass with recorded hologram was studied....
Article
The basic possibility of forming a holographic image of a two-dimensional object mark in photothermo-refractive (PTR) glass is demonstrated. The parameters of a hologram in a three-dimensional medium are calculated, and a subsequent analysis of the characteristics of the recorded mark prototype is performed. The advantages are shown of PTR glass as...
Article
Full-text available
It is shown experimentally that the morphology and ultraviolet irradiation dose required for the formation of silver nanocrystals in photo-thermo-refractive glasses on ultraviolet irradiation and subsequent heat treatment depends substantially on the concentration of nucleation centers. In turn, this concentration is predetermined by the material o...
Article
The spectral and holographic characteristics of classical and modified photothermorefractive glass are compared. It shows that modified photothermorefractive glass has no additional absorption bands in the blue–green region, as is the case in classical photothermorefractive glass. This makes it possible to record purely phase holograms in modified...
Conference Paper
Luminescent optical fibers doped with silver molecular clusters or cadmium chalcogenide quantum dots were synthesized and investigated. The fibers have a wide spectral sensitivity range required for detection of UV and shortwave visible radiation and high efficiency of waveguide modes excitation. They also can be used as electric arc and spark dete...
Article
Full-text available
It is shown experimentally that a rise in the sodium halogenide (NaCl, NaBr) concentration in photothermorefractive glasses increases the intensity of luminescence from silver neutral molecular clusters. Substitution of NaBr for NaCl with their concentration being the same shifts the luminescence band toward longer waves and raises its intensity. T...
Article
The luminescence spectra of silicate glasses with silver introduced by ion exchange have been investigated. It is shown that silver introduced into glass by ion exchange exists not only in the form of ions, but also as neutral atoms and charged and neutral molecular clusters, which provide intense luminescence in the visible spectral range. Cerium...
Article
This work is devoted to the investigation of the influence of mechanical deformation of photo-thermo-refractive glasses in the temperature range 800-1000 °C on the state of silver nanoparticles. It is shown that halide shell of the silver nanoparticles is dissolved during the sample stretching. That results in the shift and the increase of the plas...
Article
The effects of the silver ion exchange and of subsequent UV irradiation and/or heat treatment on the optical density spectra of photo-thermo-refractive matrix glass samples both virgin and doped with cerium and/or antimony oxides were investigated. The incorporation of silver by ion exchange for ~15 min at 310 °C was found to cause, for all glasses...
Article
This paper presents a comparative analysis of the luminescence and absorption of glasses with molecular clusters of silver and selenium and nanocrystals of copper chloride and cadmium sulfide from the viewpoint of spectral down-conversion of short-wavelength solar radiation into the spectral interval of the maximum efficiency of the photoelectric c...
Conference Paper
Full-text available
The paper describes the research of influence of cerium ions in a silicate glass composition on the process of formation silver nanoclusters and their optical properties. Effect ion exchange time and subsequent heat treatment at temperature below transition temperature were investigated. The paper shows that in cerium-doped glasses the rate of form...
Article
The ultraviolet-Vis absorption spectra of bromine-free and bromine-containing photo-thermo-refractive glass matrix samples doped with silver were recorded and processed with the dispersion analysis version based on the Convolution Model for the complex dielectric function of glasses. The silver-related envelope in the ultraviolet spectra of the sam...
Article
This paper presents the experimental results of a study of how temperature affects the luminescence of molecular clusters of silver in photothermorefractive glasses. It is shown that, after the glasses are UV-irradiated in the absorption band of cerium ions, intense and broad-band luminescence appears in the visible region. The luminescence centers...
Article
The luminescence spectra of photo-thermo-refractive (PTR) glasses containing cerium, silver, and antimony ions before and after UV irradiation and after heat treatment have been thoroughly investigated for the first time. It is shown that silver is present in the initial PTR glass in the form of ions and positively charged molecular clusters. After...
Article
The UV absorption spectra of cerium-doped photo-thermo-refractive matrix glasses were recorded and processed with the dispersion analysis based on Convolution model for the complex dielectric function. It was confirmed that the absorption maxima in the UV spectra of PTR matrix glasses related to the Ce3 + and Ce(IV) valence states are the envelopes...