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Experiment-based model of an Er/Yb gain medium for fiber amplifiers and lasers
Journal of the Optical Society of America B: Optical Physics. 2023. Vol. 40. No. 9. P. 2273–2279.
A model of an Er3+/Yb3+ co-doped glass gain medium is proposed. The system of rate equations taking into
account a minimum set of processes required to describe experimental data was built. As a result, a moderate number of fitting parameters is used, and thereby the model reliability is increased. For the populations of the energy
levels of Er3+ and Yb3+ ions, analytic expressions were obtained, as well as for the gain factor of the medium. The
model was validated by a series of measurements of gain in Er3+/Yb3+ fiber amplifiers of different lengths at varying
pump power. Such parameters of the model were found to fit the experimental data with an account of the spatial
inhomogeneity of thepumppower along the fiber. Themaximuminversion of erbium ion population at highpump
powers was analytically expressed, which describes the “bottleneck” effect. The power required to pump the fiber
along the entire length was found.
Keywords: fiber lasers
Budkov Y., Journal of Chemical Physics 2026 Vol. 165 No. 9 Article 094902
We derive the stress tensor of a flexible polymer solution within the Gaussian-chain self-consistent field theory (SCFT) without invoking the ground-state dominance (GSD) approximation. Starting from a covariant formulation of the single-chain partition function in a background metric, we obtain the symmetric stress tensor expressed through the full Edwards propagators. The result contains the local ...
Added: September 2, 2026
Pikina E., Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2026 Vol. 113 No. 5
In this work, we investigate the elastic properties of deflated vesicles and their shape dynamics in uniaxial extensional flow. By analyzing the Helfrich bending energy and viscous flow stresses in the limit of highly elongated shapes, we demonstrate that all stable vesicle configurations are metastable. For vesicles with small reduced volume, we identify the type ...
Added: September 1, 2026
Chernyshov A., Padokhin A. M., Grach S. M. et al., Geophysical Research Letters 2026 Vol. 53 P. 1–11
This paper presents the first results of a coordinated experiment on the ionospheric plasma response to high-frequency (HF) overdense heating, conducted using the SURA heating facility and the Ionosfera-M satellite. The experiment combined ground-based observations with in situ satellite measurements, enabling a comprehensive study of artificial ionospheric disturbances. During the experiment, the SURA facility transmitted ...
Added: August 31, 2026
D. A. Dorofeev, A. A. Chernyshov, Mogilevsky M. M. et al., JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 2025 Vol. 130 Article e2025JA033900
This study analyzes data from the ERG (Arase) satellite over a period of nearly 7 years (2017–2023). During this time, about 1,000 cases of hectometric continuum (HMC) radiation in near‐Earth space were detected, which made it possible to identify characteristic features on different time scales. On a daily scale, it was established that HMC is ...
Added: August 31, 2026
Mogilevsky M. M., Shaposhnikov V., Chernyshov A. et al., Physics of Plasmas 2025 Vol. 32 P. 1–10
The ERG (Arase) satellite recently discovered a non-thermal hectometric continuum with a narrowband frequency structure. The mechanism behind the generation of this type of emission in the near-Earth plasma is still unknown. This study examines the potential use of electron cyclotron harmonics instability to explain the line structure of hectometric radio emissions for the first ...
Added: August 31, 2026
Kobtsev Danil, Albert J., Nitzan M. et al., Applied Sciences (Switzerland) 2026 Vol. 16 No. 17 Article 8577
AIVBVI semiconductors, particularly lead chalcogenides, remain key materials for mid-wave infrared (MWIR) photodetection due to their narrow bandgap and exceptional carrier transport properties. However, the realization of high-quality p-type PbTe thin films, suitable for p–n junction devices, remains a technological challenge. In this work, we report the fabrication of high-mobility p-type PbTe thin films grown on ...
Added: August 30, 2026
Воронеж: Издательский дом ВГУ, 2026.
В сборник вошли материалы XXXII Международной научно-технической конференции «Радиолокация, навигация, связь» (RLNC*2026), прошедшие ре цензирование членами программного комитета конференции. Основной целью конференции является организация взаимодействия научных и научно технических коллективов для обмена опытом и новыми творческими успехами. Достижение этой цели также способствует внедрению перспективных разрабо ток, имеющих практическое значение для дальнейшего развития промышленно сти, экономики ...
Added: August 29, 2026
Melnikov I., Pelinovsky E., Nonlinear Dynamics 2026 No. 114 Article 934
Pyramidal solitons (solitons with more than two inflection points) of the generalized Korteweg–de Vries (KdV) equation are investigated. Necessary and sufficient conditions for the existence of such structures are presented. Within the framework of the generalized Gardner equation — the simplest model that admits pyramidal solitons as solutions — it is shown that these solutions ...
Added: August 27, 2026
Zhukov A., Kryzhanovskaya N., Moiseev E. et al., Nature 2026 Vol. 656 P. 80–85
Reaching lasing in electrically pumped microdevices based on solution-processed
semiconductors poses a substantial scientific and technological challenge. Halide
perovskites offer a promising platform for electrical injection1, as their optically
excited single-crystal cavities2–4 and predesigned5,6 or postprocessed microstructures7,8
have exhibited low lasing threshold. Indirect electrical pumping of a dual-cavity
perovskite laser was recently obtained9, using a well-established technological
concept of embedding a ...
Added: August 27, 2026
Mazur D., Brandyshev P., Doronin S. V. et al., Electrochimica Acta 2026 Vol. 577 Article 149729
The electric double layer (EDL) at a single-crystal metal surface is controlled not only by the electrolyte composition and the electrode potential, but also by the atomic structure of the surface itself. This makes the Ag(hkl)/NaF interface a stringent test for continuum theories of the EDL. In the third part of our series, we examine ...
Added: August 20, 2026
Gimaev R., Karpenkov A., Shelkovyi F. et al., Journal of Alloys and Compounds 2026 No. 1080 Article 190307
The magnetothermal properties of the quaternary Fe49Rh46.1Pd3.1Ir1.8 alloy are investigated by a combination of first-principles calculations, structural characterization, magnetometry, calorimetry, and direct measurements of the adiabatic temperature change. An exceptional magnetocaloric response is obtained, with ΔTad reaching −11.9 K in a field of 1.85 T under the discontinuous protocol and −8.6 K under the continuous ...
Added: August 18, 2026
Beck M. E., Seidov S., Mukhin S., Physical Review A: Atomic, Molecular, and Optical physics 2026 Vol. 113 No. 6 Article 063706
Quantum dissipation is studied in the superradiant phase of the extended Dicke model. It is demonstrated analytically by quantum mechanical derivation of the Lindblad equation for the Dicke model in the superradiant state coupled to Caldeira-Leggett thermal bath that the effective viscosity appearing in the semiclassical equations of motion of polaritonic condensate survives in the zero-temperature limit ...
Added: August 13, 2026
S. S. Seidov, N. G. Pugach, Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 114 No. 7 Article 074504
In this manuscript we consider a superconducting film in the vicinity of the critical temperature and presence of the proximity effect. We analytically solve the corresponding linearized Usadel equation and the self-consistency equation, defining the critical temperature. This is a system of coupled differential and integral equations for the anomalous Green's function and the order parameter of ...
Added: August 13, 2026
Ievlev E., Marshakov A., Sumbatian G. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2026 Vol. 114 Article 046006
We continue the study of non-Abelian vortex string in 4D N =2 supersymmetric QCD (SQCD) as
critical superstring, and extend this analysis to UðNÞ gauge theory with arbitrary even N and Nf = 2N
number of quarks. We introduce a special mass deformation and show that the SQCD hadron spectrum is
still given by the string spectrum on the ...
Added: August 13, 2026
Afanasiev S., Agakishiev G., Aleksandrov A. et al., Journal of High Energy Physics 2026 Vol. 2026 Article 48
The BM@N experiment (Baryonic Matter at the Nuclotron) is the first fixed-target experiment at the JINR NICA accelerator complex. In this work, data on the interactions of a carbon-ion beam with kinetic energies of 4.0A GeV and 4.5A GeV with C, Al, Cu, and Pb targets are used to measure transverse momentum spectra and rapidity ...
Added: August 12, 2026
Budkov Y., Kalikin N., Journal of Chemical Physics 2026 Vol. 165 Article 064506
A self-consistent statistical-mechanical theory of the Hall effect in electrolyte solutions is developed by extending the self-consistent Debye–Hückel–Onsager (SCDHO) framework to crossed electric and magnetic fields. The theory incorporates non-local ionic charge distributions via Slater-type form factors, regularizing the Coulomb interaction at short range, and accounts for dielectric friction through ion-specific coefficients, employing experimental values ...
Added: August 12, 2026
Ali S., Bocharnikov V., Ratnikov F. et al., Sensors 2026 Vol. 26 No. 16 Article 5024
Large distributed sensor arrays require repeated recalibration as radiation damage, material aging, gain variation, and readout drift alter channel responses. We studied a high-granularity calorimeter as a large sensor array and addressed unsupervised recalibration from two unpaired datasets: a nominal reference response and an aged response with attenuated cell-wise signals. Aging was modeled by a ...
Added: August 11, 2026
Ponomarev A., Aleksandrov N., Journal of Physics D: Applied Physics 2026 Vol. 59 No. 31 Article 315205
Electron attachment and detachment in H2O:O2 and H2O:air mixtures are theoretically studied at moderate (40–100 Td) reduced electric fields. It is shown that there are two synergistic mechanisms of ultra-rapid electron detachment from negative ions in these mixtures, whereas these detachment channels are absent in pure gases. Effective attachment coefficient calculated with consideration for fast ion–molecule ...
Added: August 6, 2026
Khrapai V., Tikhonov E., Nature Physics 2026 P. 1198–1199
Feng et al.1 presented transport measurements of three-terminal normal–superconductor–normal devices based on topological insulator nanowires. They measured the full differential conductance matrix, defined as Gij = ∂Ii /∂Vj , beyond the linear response regime as a function of various control parameters. Here i, j∈ [1, 2] denote normal terminals biased by the voltages V1 and ...
Added: August 5, 2026
G. G. Bondarenko, Kristya V. I., Savichkin D. O. et al., Journal of Surface Investigation: X-Ray, Synchrotron and Neutron Techniques 2026 Vol. 20 No. 2 P. 417–423
A model of a glow gas discharge in a mixture of argon and mercury vapor is formulated in the presence
of a thin insulating film on the cathode surface. Dependences of the discharge characteristics on the
mixture temperature are calculated in the range of its variation, in which a noticeable contribution to ionization
of the working gas is ...
Added: August 1, 2026
Касимов Р. Х., Аржанов А. И., Седых К. О. et al., Оптический журнал 2026 Т. 93 № 1 С. 80–86
Предмет исследования. Использование метода капельного нанесения для изготовления источника одиночных фотонов. Цель работы. Разработка технологического процесса изготовления источника одиночных фотонов на коллоидных квантовых точках для использования их в фотон- ных интегральных схемах. Метод. На первом этапе в программе ANSYS Lumerical рассчитыва- ются период и фактор заполнения фокусирующих элементов связи на длинах волн 545 и 600 ...
Added: July 31, 2026
Nevzorov A., Golikov A., Gneushev D. et al., JETP Letters 2026 Vol. 123 No. 3 P. 147–151
This paper demonstrates a special stochastic operation mode of a photonic element with a thin GeTe film deposited at a silicon nitride waveguide. As opposed to traditional deterministic switching between stable states, it has been shown that identical pump laser pulses cause a stochastic change in the transmission coefficient. The discovered effect opens up new ...
Added: July 31, 2026
Rybaltovsky A. A., O. V. Butov, Vasiliev S. A. et al., Results in Physics 2020 Vol. 16 Article 102832
In the paper we investigate the characteristics of a short-cavity fiber laser based on a new silica fiber with a composite erbium-doped phosphosilicate core without additional co-doping with ytterbium. For the first time, the operation of such laser in the continuous-wave lasing mode with 1490-nm pump is shown. The laser operation in the self-Q-switching mode, ...
Added: October 21, 2022
Rybaltovsky A. A., Lipatov D. S., Lobanov A. S. et al., Journal of the Optical Society of America B: Optical Physics 2020 Vol. 37 No. 10 P. 3077–3083
Highly Er/Yb co-doped phosphosilicate fibers with lowoptical losseswere fabricated by theMCVDmethod, utilizing an all-gas-phase deposition technique developed “in house.” Important characteristics such as photodarkening and photosensitivity of these fibers were thoroughly investigated. An almost negligible impact of photodarkeninginduced losses (no more than 1 dB/m) was discovered in the near-infrared spectral region. The photosensitivity of hydrogen-loaded ...
Added: October 21, 2022