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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">mireabulletin</journal-id><journal-title-group><journal-title xml:lang="ru">Russian Technological Journal</journal-title><trans-title-group xml:lang="en"><trans-title>Russian Technological Journal</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">2782-3210</issn><issn pub-type="epub">2500-316X</issn><publisher><publisher-name>RTU MIREA</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.32362/2500-316X-2026-14-3-115-130</article-id><article-id custom-type="edn" pub-id-type="custom">MYWEJW</article-id><article-id custom-type="elpub" pub-id-type="custom">mireabulletin-1542</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>MATHEMATICAL MODELING</subject></subj-group></article-categories><title-group><article-title>Особенности аналитического моделирования нелинейных поверхностных волн в градиентных средах</article-title><trans-title-group xml:lang="en"><trans-title>Features of analytical modeling of nonlinear surface waves in gradient media</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-7158-9145</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Савотченко</surname><given-names>С. Е.</given-names></name><name name-style="western" xml:lang="en"><surname>Savotchenko</surname><given-names>S. E.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Савотченко Сергей Евгеньевич, д.ф.-м.н., доцент, профессор кафедры высшей математики – 3, Институт перспективных технологий и индустриального программирования </p><p>Scopus Author ID 6603577988, SPIN-код РИНЦ 2552-4344 </p><p>119454, Москва, пр-т Вернадского, д. 78 </p></bio><bio xml:lang="en"><p>Sergey E. Savotchenko, Dr. Sci. (Phys.-Math.), Associate Professor, Professor, High Mathematics Department – 3, Institute for Advanced Technologies and Industrial Programming</p><p>Scopus Author ID 6603577988</p><p>78, Vernadskogo pr., Moscow, 119454 </p></bio><email xlink:type="simple">savotchenkose@mail.ru</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0009-0009-0044-7930</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Афанасьева</surname><given-names>Н. О.</given-names></name><name name-style="western" xml:lang="en"><surname>Afanasyeva</surname><given-names>N. O.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Афанасьева Надежда Олеговна, аспирант, кафедра высшей математики и физики </p><p>117997, Москва, ул. Миклухо-Маклая, д. 23</p></bio><bio xml:lang="en"><p>Nadezhda O. Afanasyeva, Postgraduate Student, High Mathematics and Physics Department</p><p>23, Miklukho-Maklaya ul., Moscow, 117997</p></bio><email xlink:type="simple">noafanasieva@mail.ru</email><xref ref-type="aff" rid="aff-2"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>МИРЭА – Российский технологический университет</institution><country>Россия</country></aff><aff xml:lang="en"><institution>MIREA – Russian Technological University</institution><country>Russian Federation</country></aff></aff-alternatives><aff-alternatives id="aff-2"><aff xml:lang="ru"><institution>Российский государственный геологоразведочный университет им. Серго Орджоникидзе</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Sergo Ordzhonikidze Russian State Geological Prospecting University</institution><country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2026</year></pub-date><pub-date pub-type="epub"><day>02</day><month>06</month><year>2026</year></pub-date><volume>14</volume><issue>3</issue><fpage>115</fpage><lpage>130</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Савотченко С.Е., Афанасьева Н.О., 2026</copyright-statement><copyright-year>2026</copyright-year><copyright-holder xml:lang="ru">Савотченко С.Е., Афанасьева Н.О.</copyright-holder><copyright-holder xml:lang="en">Savotchenko S.E., Afanasyeva N.O.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://www.rtj-mirea.ru/jour/article/view/1542">https://www.rtj-mirea.ru/jour/article/view/1542</self-uri><abstract><sec><title>Цели</title><p>Цели. Важную роль в современной физике и волноводной оптике играют и исследования, связанные с нахождением точных решений используемых при моделировании уравнений, позволяющие выявить классы точно решаемых моделей. Цель работы – изучение свойств поверхностных поперечных волн, распространяющихся вдоль границы раздела нелинейной и градиентной немагнитных сред без потерь.</p></sec><sec><title>Методы</title><p>Методы. В работе использованы методы математического моделирования, методы анализа и математической физики, дифференциальных уравнений и теории специальных функций. Использовались базовые принципы, методы и физические модели нелинейной и волноводной оптики.</p></sec><sec><title>Результаты</title><p>Результаты. Проведено моделирование свойств поверхностных поперечных волн, распространяющихся вдоль границы раздела нелинейной и градиентной сред. В качестве модели нелинейности среды, описывающей нелинейно-оптический отклик среды на возмущения электрического поля, выбрана линейная форма зависимости диэлектрической проницаемости от интенсивности света. В качестве модели градиентной среды выбрана форма пространственного профиля диэлектрической проницаемости, описывающая ее изменение в зависимости от расстояния до границы раздела, для которой можно найти точное аналитическое решение стационарного волнового уравнения. Приведена математическая формулировка модели, которая представляет собой краевую задачу сопряжения для нелинейного уравнения с переменными коэффициентами. Найдены точные аналитические решения данной краевой задачи для случаев фокусирующей и дефокусирующей нелинейностей, которые описывают пространственные распределения напряженности электрического поля в поперечном границе раздела сред направлении. Анализ модели позволил выявить существенные различия пространственного распределения интенсивности поля в поверхностных волнах, распространяющихся в фокусирующих и дефокусирующих средах. Проведен детальный анализ влияния значений параметров модели, характеризующих оптические свойства контактирующих сред, на пространственное распределение интенсивности света в поверхностных волнах.</p></sec><sec><title>Выводы</title><p>Выводы. Полученные результаты дополняют существующую теорию нелинейной и волноводной оптики и могут найти применение при проектировании новых волноводных структур с определяемыми пользователями свойствами. Полученные новые решения расширяют класс точно решаемых моделей планарных волноводных структур с распределенными неоднородными и нелинейными свойствами.</p></sec></abstract><trans-abstract xml:lang="en"><sec><title>Objectives</title><p>Objectives. An important role in modern physics, particularly in waveguide optics, is played by studies that involve the search for exact solutions to equations used in modeling to identify classes of exactly solvable models. This work set out to use analytical modeling methods to explore the properties of surface shear waves propagating without loss along the interface between a nonlinear and a graded-index nonmagnetic medium.</p></sec><sec><title>Methods</title><p>Methods. Methods of mathematical modeling, calculus, mathematical physics, differential equations, and the theory of special functions were used. Fundamental principles, methods, and physical models of nonlinear and waveguide optics were also applied.</p></sec><sec><title>Results</title><p>Results. The properties of surface transverse waves propagating along the interface between a nonlinear and a graded-index medium are modeled. In order to model the nonlinearity of the medium to describe the nonlinear optical response of the medium to electric field perturbations, the linear dependence of permittivity on light intensity is chosen as a parameter. The graded-index medium is modeled using a spatial profile of permittivity as a function of distance from the interface for which an exact analytical solution to the stationary wave equation can be found. A mathematical formulation of the model is presented, consisting of a conjugation boundary value problem for a nonlinear equation with variable coefficients. Exact analytical solutions to this boundary value problem are found for the cases of focusing and defocusing nonlinearities to describe the spatial distributions of the electric field strength in the direction transverse to the interface. Analysis of the model revealed significant differences in the spatial distribution of the field intensity in surface waves propagating in the focusing and defocusing media. The effect of the values of model parameters used to characterize the optical properties of the contacting media on the spatial distribution of light intensity in surface waves was also studied in detail.</p></sec><sec><title>Conclusions</title><p>Conclusions. The obtained, which results supplement the existing theory of nonlinear and waveguide optics, can be applied in the design of new waveguide structures with user-defined properties. The obtained new solutions expand the class of exactly solvable models of planar waveguide structures with distributed inhomogeneous and nonlinear properties.</p></sec></trans-abstract><kwd-group xml:lang="ru"><kwd>математическое моделирование</kwd><kwd>математическая модель</kwd><kwd>краевая задача</kwd><kwd>точное решение</kwd><kwd>поверхностная волна</kwd><kwd>волноводная оптика</kwd><kwd>нелинейная оптика</kwd></kwd-group><kwd-group xml:lang="en"><kwd>mathematical modeling</kwd><kwd>mathematical model</kwd><kwd>boundary value problem</kwd><kwd>exact solution</kwd><kwd>surface wave</kwd><kwd>waveguide optics</kwd><kwd>nonlinear optics</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Боголюбов А.Н., Мосунова Н.А., Петров Д.А. Математические модели киральных волноводов. 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