S. M. Bobrovnikov, L. A. Bolbasova, E. V. Gorlov, V. I. Zharkov, V. P. Lukin
{"title":"Comparison of the Efficiency of Sodium Atom Excitation Schemes for Generating Monochromatic and Polychromatic Laser Guide Stars","authors":"S. M. Bobrovnikov, L. A. Bolbasova, E. V. Gorlov, V. I. Zharkov, V. P. Lukin","doi":"10.3103/S1068335624601390","DOIUrl":"10.3103/S1068335624601390","url":null,"abstract":"<p>The efficiency of ten sodium atom excitation schemes that can potentially be used to generate a sodium polychromatic laser guide star (PLGS) and a monochromatic laser guide star (LGS) is compared. It is shown that for creating an LGS in sodium vapor using the cascade fluorescence effect with single-photon excitation, the most suitable is the 4<sup>2</sup>P<sub>3/2</sub> ← 3<sup>2</sup>S<sub>1/2</sub> transition excited at a wavelength of 330.237 nm and demonstrating the highest LGS characteristics, while the efficiency decreases by two orders of magnitude compared to a monochromatic LGS at a wavelength of 588.995 nm.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"51 5 supplement","pages":"S351 - S364"},"PeriodicalIF":0.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Phase and Group Velocities of X-ray Waves in the Pores of Track Membranes","authors":"A. V. Mitrofanov, R. M. Feshchenko","doi":"10.3103/S1068335624601468","DOIUrl":"10.3103/S1068335624601468","url":null,"abstract":"<p>Propagation of electromagnetic hard X-ray waves inside cylindrical pores in thin polyethylene terephthalate (PET) track membranes is studied. Numerical simulation shows that both the phase and group velocities of the waves are constant over a significant part of the through pore length. In this case, the product of the phase and group velocities is equal to the square of the speed of light in vacuum. The paper analyzes the relationship between the established properties of wave velocities in pores and the properties of waveguide modes propagating in a hollow cylindrical waveguide with smooth walls. Possible applications of the observed phase properties of the pores for fabricating phase X-ray filters based on porous PET membranes are discussed.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"51 5 supplement","pages":"S416 - S423"},"PeriodicalIF":0.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. G. Vitukhnovskii, A. O. Kolesnikov, D. A. Kolymagin, E. N. Ragozin, A. N. Shatokhin
{"title":"3D Laser Lithography Technique in the Fabrication of a Coherent 2D Kinoform X-ray Lens","authors":"A. G. Vitukhnovskii, A. O. Kolesnikov, D. A. Kolymagin, E. N. Ragozin, A. N. Shatokhin","doi":"10.3103/S1068335624601456","DOIUrl":"10.3103/S1068335624601456","url":null,"abstract":"<p>An analytical expression is obtained for the shape of a coherent kinoform X-ray lens surface, which is different from a parabola. A lens with a focal length of 1 m for monochromatic radiation with a photon energy of 12 keV is calculated. Two refractive lens materials—Rose’s alloy and silver—are selected. With a lens diameter of 200 μm, the diameter of the central diffraction maximum at the focus, calculated using the Huygens–Fresnel principle, is about 1 μm. The fraction of the light flux power incident on the lens in the central diffraction maximum of the focal spot is 14.6% for Rose’s alloy and 16.1% for silver. The capabilities of the femtosecond two-photon nanolithography developed at the Lebedev Physical Institute and Moscow Institute of Physics and Technology for producing efficient kinoform lenses for synchrotron radiation X-ray microscopy are demonstrated.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"51 5 supplement","pages":"S424 - S433"},"PeriodicalIF":0.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Light Localization Effects in a Quasi-Homogeneous Rhombic Waveguide Array","authors":"O. V. Korovai, D. A. Markov","doi":"10.3103/S1068335624601432","DOIUrl":"10.3103/S1068335624601432","url":null,"abstract":"<p>Use is made of the coupled-mode method to theoretically study the effects of laser radiation propagation in a quasi-one-dimensional rhombic waveguide array consisting of three parallel waveguide arrays, with the interaction of each waveguide with its nearest neighbors and between the waveguides of the arrays taken into account. Analytical expressions are derived that allow one to accurately predict the occurrence of the light localization effect in relation to the values of the coupling constants. It is shown that the spectrum of linear waves in the system has one flat band. A particular solution of the system of coupled-wave equations is obtained, which describes strongly localized radiation propagating without transverse diffraction along the entire array. The parameter values are found for which the Anderson localization effect is observed in the rhombic array.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"51 5 supplement","pages":"S395 - S407"},"PeriodicalIF":0.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dynamics of Atomic Population Gratings in Collisions of Unipolar Light Pulses in a Multilevel Resonant Medium","authors":"R. M. Arkhipov","doi":"10.3103/S1068335624601407","DOIUrl":"10.3103/S1068335624601407","url":null,"abstract":"<p>We report an analytical and numerical study of the dynamics of electromagnetically induced atomic population gratings during collisions of a sequence of unipolar pulses of unusual temporal shape (rectangular and triangular) in a multilevel resonant medium. The possibility of forming dynamic microcavities with Bragg-like mirrors, the shape of which is different at each resonant transition of the medium, is demonstrated. A simple analytical description of such microresonators is proposed based on an approximate solution of the time-dependent Schrödinger equation when the amplitude of the exciting pulses is small. In the case of high-power pulses, when perturbation theory is not applicable, the results of numerical calculations show the disappearance of microcavities and the emergence of nonharmonic gratings with an increase in the number of collisions between pulses. The studied phenomena demonstrate a possibility of using unipolar pulses of an unusual shape for ultrafast control of the medium properties.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"51 5 supplement","pages":"S365 - S373"},"PeriodicalIF":0.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yu. A. Adamenkov, M. A. Gorbunov, E. V. Kabak, A. A. Kalacheva, V. A. Shaidulina, A. V. Yur’ev
{"title":"Simultaneous Generation at Three Wavelengths in an Optically Pumped He–Kr–Ar Medium","authors":"Yu. A. Adamenkov, M. A. Gorbunov, E. V. Kabak, A. A. Kalacheva, V. A. Shaidulina, A. V. Yur’ev","doi":"10.3103/S1068335624601493","DOIUrl":"10.3103/S1068335624601493","url":null,"abstract":"<p>The results of experiments with a model of an optically pumped rare-gas laser are presented. Laser generation was produced simultaneously at three wavelengths (912.3, 893.1, and 877.7 nm) using a gas mixture consisting of 98% He (buffer gas), 1.5% Ar, and 0.5% Kr. Dependence of generation power and of the ratio of the intensities of individual lines in total generation on consumption of the gas mixture, on cuvette pressure, and on the discharge pulse repetition rate has been studied experimentally. The maximum laser power (the sum of all the wavelengths) was ~8 mW.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"51 5 supplement","pages":"S374 - S380"},"PeriodicalIF":0.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. R. Butaev, V. I. Kozlovsky, Ya. K. Skasyrsky, N. R. Yunusova
{"title":"Determination of the Diffusion Length of Nonequilibrium Carriers in CdS/ZnSe/ZnSSe Heterostructures Designed for Semiconductor Disk Lasers","authors":"M. R. Butaev, V. I. Kozlovsky, Ya. K. Skasyrsky, N. R. Yunusova","doi":"10.3103/S1068335624601419","DOIUrl":"10.3103/S1068335624601419","url":null,"abstract":"<p>Cathodoluminescence of a heterostructure with CdS/ZnSe/ZnSSe quantum wells at different electron energies in the range of 3–7 keV has been studied. The dependence of the ratio of the radiation intensity of the quantum well to the intensity of radiation of the ZnSSe barrier layers matched to the GaAs substrate is obtained. This relationship is modeled for different diffusion lengths of nonequilibrium charge carriers in barrier layers and coefficients of trapping of these carriers by a quantum well. It is shown that taking the surface recombination into account gives the best modeling results. An estimate of the diffusion length of nonequilibrium carriers in barrier layers of 25 nm was obtained from comparing the simulation results and the experimental data. The effect of the diffusion length on the characteristics of a semiconductor disk laser based on heterostructures with similar quantum wells is discussed.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"51 5 supplement","pages":"S381 - S388"},"PeriodicalIF":0.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. A. Murzakov, N. N. Evtikhiev, N. V. Grezev, D. M. Kataev, D. A. Antipov, D.V. Bindyug
{"title":"Study on the Effect of Focusing Parameters of Ultrashort Pulses on the Process of Laser Welding of Transparent Materials with Metals","authors":"M. A. Murzakov, N. N. Evtikhiev, N. V. Grezev, D. M. Kataev, D. A. Antipov, D.V. Bindyug","doi":"10.3103/S1068335624601225","DOIUrl":"10.3103/S1068335624601225","url":null,"abstract":"<p>We study the effect of optical focusing parameters of picosecond laser pulses (1–3 ps) on the process of forming a welded joint between transparent materials and metals. It is found that when use is made of lenses with a numerical aperture NA = 0.25, there is no stable formation of welded joints, in contrast to the use of an F-Theta lens with a focal length of 100 mm (NA = 0.05). Welds are tested for shear; the average values of the strength of welded joints are in the range from 5 to 15 MPa. Thermal cycling tests of welded samples are performed in the temperature range from –10 to 60°C. A study of welded joints using a scanning electron microscope reveals that the glass–metal interaction region is 250 nm. For the first time, a T-joint welding of a quartz mirror element to an invar substrate is performed, which significantly increases the application of this technology in industry, especially for instrument-making and optics.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"51 4 supplement","pages":"S297 - S304"},"PeriodicalIF":0.6,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. V. Bourdine, M. V. Dashkov, V. V. Demidov, A. S. Evtushenko, E. S. Zaitseva, G. A. Pchelkin, E. V. Ter-Nersesyants, K. V. Dukelskii
{"title":"Silica Multicore Microstructured Optical Fibers with Induced Twisting","authors":"A. V. Bourdine, M. V. Dashkov, V. V. Demidov, A. S. Evtushenko, E. S. Zaitseva, G. A. Pchelkin, E. V. Ter-Nersesyants, K. V. Dukelskii","doi":"10.3103/S1068335624601201","DOIUrl":"10.3103/S1068335624601201","url":null,"abstract":"<p>We present a new class of optical fibers: silica chiral multicore microstructured optical fibers (MOFs) characterized by twisting induced during the drawing process and the use of supporting elements made of GeO<sub>2</sub>-doped silica glass. Technological aspects of core preform manufacturing, as well as specific features of the implementation of drawing the lengths of twisted MOFs, are considered. The technical feasibility of the described complex fiber-optic structure is confirmed. Extended (50 m long) pilot samples of silica six-core MOFs with step- and graded-index profiles of the cores and different twisting degrees from 50 to 500 rpm are manufactured for the first time, and the results of measuring their basic characteristics are presented.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"51 4 supplement","pages":"S274 - S289"},"PeriodicalIF":0.6,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. V. Zorina, S. A. Garakhin, A. O. Kolesnikov, E. N. Ragozin, A. A. Solov’ev, A. N. Shatokhin
{"title":"Transportable Soft X-ray Flat-Field Spectrograph","authors":"M. V. Zorina, S. A. Garakhin, A. O. Kolesnikov, E. N. Ragozin, A. A. Solov’ev, A. N. Shatokhin","doi":"10.3103/S1068335624601304","DOIUrl":"10.3103/S1068335624601304","url":null,"abstract":"<p>We report fabrication and testing of a transportable version of a high-resolution flat-field spectrograph. The device uses two replaceable grazing-incidence VLS gratings with central densities of 1200 and 2400 lines mm<sup>–1</sup>, producing a flat field in the wavelength ranges of 5–28 nm and 2.5–14 nm, respectively. The plate scale is about 0.56 and 0.28 nm/mm at a wavelength of 12 and 6 nm for the first and second gratings, respectively. The VLS gratings are fabricated by interference lithography. The grating efficiency at a wavelength of 12.5 nm is measured by a reflectometer with a laser-plasma source of soft X-ray radiation. During the tests of the spectrograph, line spectra of multiply charged ions in a plasma excited by nanosecond laser radiation are obtained. The spectrograph is designed to record soft X-ray radiation excited by a multiterawatt femtosecond laser in various targets.</p>","PeriodicalId":503,"journal":{"name":"Bulletin of the Lebedev Physics Institute","volume":"51 4 supplement","pages":"S337 - S344"},"PeriodicalIF":0.6,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}