Исследование температурного оптического коэффициента золь-гель волноводов

Review of methods for studying temperature dependence of characteristics of optical waveguides fabricated by sol-gel technique is presented. The method of studying temperature properties of effective refractive index of waveguide modes with the help of thermoelectric module Peltier is proposed and approved. This method allows to widely expand the temperature researches of materials and waveguides made of them.Проведён и систематизирован обзор методов исследования температурной зависимости характеристик оптических волноводов на основе плёнок, изготовленных по золь-гель технологии. Предложена и опробована методика температурных исследований эффективного показателя преломления волноводных мод с помощью термоэлектрического модуля Пельтье. Данная методика отличается простотой и удобством и при этом позволяет существенно расширить возможности температурных исследований волноводов и материалов, из которых они изготовлены

Waveguide spectral multiplexers/demultiplexers

Configurations, basic characteristics, and the methods for implementation of wavelength-division multiplexers/demultiplexers as the key elements of the end stations in fiber-optics communication systems are considered. The most important studies directed at practical implementation of wavelength-division multiplexers in specific devices based on SiO2 and InP are reviewed in detail. SiO2-based multiplexers exhibit lower losses, whereas devices based on InP make it possible to use the technologies of microelectronics and integrating optics and to fabricate radiation sources and passive components on the same substrate. Schemes for optical multiplexers with adding and dropping of channels and examples of their implementation are given. It is emphasized that high-density wavelength-division multiplexers have small sizes and are fabricated by conventional lithography, which makes them promising in wideband optical communication systems. ©2000 Kluwer Academic/Plenum Publishers

Large-scale fibre-array multiplexing

The possibility of creating a fibre multiplexer/demultiplexer with large-scale multiplexing without any basic restrictions on the number of channels and the spectral spacing between them is shown. The operating capacity of a fibre multiplexer based on a four-fibre array ensuring a spectral spacing of 0.7 pm (∼ 10 GHz) between channels is demonstrated

ВОЛОКОННО-ОПТИЧЕСКИЙ АНАЛИЗАТОР СПЕКТРА

A fiber-optic spectrum analyzer (FOSA) based on the principle of Michelson's echelon has been studied. Segments of optical fibers have been chosen as an analog to the plates of the classical Michelson's echelon and their lengths have been increased sequentially by a given quantity. The resolution of the FOSA due to the exceptionally low losses of the optical fibers can exceed substantially that of the classical Michelson's echelons. In the experimental model the FOSA demonstrated resolution of the He-Ne laser longitudinal modes with the spacing between them equal to 0.8 pm.Исследован волоконно-оптический анализатор спектра (ВОАС) типа эшелона Майкельсона. Аналогом пластин классического эшелона Майкельсона служили отрезки волоконных световодов, длина которых последовательно увеличивалась на заданную величину. Разрешающая способность ВОАС в силу исключительно малых потерь волоконных световодов может значительно превышать разрешающую способность классических эшелонов Майкельсона. На изготовленном макете ВОАС продемонстрировано разрешение продольных мод гелий-неонового лазера с межмодовым расстоянием 0,8 пм

Features of Propagation of Electromagnetic Waves in Sol-Gel Optical Waveguides under Varying Temperature

Abstract: Features of the temperature dependence of effective refractive index neff (ERI) of optical waveguides based on sol-gel materials have been studied and behavior of the ERI temperature coefficient (TC) have been determined. It has been found experimentally and theoretically that, with properly selected film parameters, the ERI TC can have a negative, zero, or even small positive value within a certain temperature range. Clear mathematical description of the dependence of the ERI TC on the waveguide parameters and the partial power of the wave in the waveguide has been given. © 2018, Pleiades Publishing, Inc

Waveguide Sensors for Measuring Concentrations of Components in Gas Mixtures and Liquids

Optical diagrams of waveguide sensors for measuring concentrations of components in gas mixtures and liquids are considered. The characteristics of the absorption cells of several waveguide systems are calculated as functions of parameters of optical waveguide. An ammonia waveguide sensor based on a Ta2O5 film deposited on a glass substrate is considered. The sensitivity of the sensor is 6 × 10-6. Methods for increasing the sensitivity of the sensor are suggested

Crosstalk reduction in multiplexers/demultiplexers by correction of optical paths of waveguide arrays

The issues of development of waveguide optical systems of multiplexing/demultiplexing based on waveguide phased arrays are considered with the aim of increasing the number of channels of fiberoptics communication lines and creation of systems with dense and superdense channel multiplexing. The factors that limit the increase in the channel number are determined. The role of the phase and amplitude errors resulting from the fluctuations of parameters of waveguide matrices in the course of their manufacture is demonstrated. Ways of solving the problem of reducing the phase errors by correcting the optical path of the array elements are considered. An analytical survey of correction methods based on various physical effects is carried out

Оптические свойства композитных сред с металлическими наночастицами различной формы

The work is devoted to the study of optical absorption and transmission spectra of composite media containing spherical and non-spherical metallic gold particles using the Maxwell Garnett model of an effective medium. The dependence of resonance absorption on the spatial orientation of non-spherical particles is revealed. The dispersion dependences for the reflection and transmission coefficients are calculated at different angles of incidence of radiation. A shift of the absorption maximum to the short-wavelength region of the spectrum was detected when the angle of incidence deviated from the normal.Работа посвящена исследованию оптических спектров поглощения и пропускания композитных сред, содержащих металлические частицы золота сферической и несферической формы с использованием модели эффективной среды Максвелла Гарнетта. Выявлена зависимость резонансного поглощения от пространственной ориентации частиц несферической формы. Рассчитаны дисперсионные зависимости для коэффициентов отражения и пропускания при разных углах падения излучения. Обнаружен сдвиг максимума поглощения в коротковолновую область спектра при отклонении угла падения от нормали

Temperature-independent waveguide spectral multiplexers/demultiplexers

The possibility of creating spectral multiplexers/demultiplexers with temperature-independent parameters is considered. The reasons for the temperature shift of the central wavelength of waveguide arrays of multiplexers/demultiplexers, optical filters, Mach-Zehnder interferometers, and others are analyzed. The results of studies of various techniques of wavelength stabilization of integrated-optical spectral devices and the evaluation of the efficiency of each of them are presented. The prospects of using media with a negative temperature coefficient for creation of waveguide devices are shown. © Springer Science+Business Media, Inc. 2005