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Search Results: 1 - 10 of 130310 matches for " V.Prajzler "
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Optical Splitters Based on Self-Imaging Effect in Multi-Mode Waveguide Made by Ion Exchange in Glass
O. Barkman,V.Jerabek,V.Prajzler
Radioengineering , 2013,
Abstract: Design and modeling of single mode optical multi-mode interference structures with graded refractive index is reported. Several samples of planar optical channel waveguides were obtained by Ag+<->Na+ and K+<->Na+ one step thermal ion exchange process in molten salt on GIL49 glass substrate and new special optical glass for ion exchange technology. Waveguide properties were measured by optical mode spectroscopy. Obtained data were used for further design and modeling of single mode channel waveguide and subsequently for the design of 1 to 3 multimode interference power splitter in order to improve simulation accuracy. Designs were developed by utilizing finite difference beam propagation method.
Design and Modeling of Symmetric Three Branch Polymer Planar Optical Power Dividers
V. Prajzler,H. Tuma,J. Spirkova,V. Jerabek
Radioengineering , 2013,
Abstract: Two types of polymer-based three-branch symmetric planar optical power dividers (splitters) were designed, multimode interference (MMI) splitter and triangular shape-spacing splitter. By means of modeling the real structures were simulated as made of Epoxy Novolak Resin on silicon substrate, with silica buffer layer and polymethylmethacrylate as protection cover layer. The design of polymer waveguide structure was done by Beam Propagation Method. After comparing properties of both types of the splitters we have demonstrated that our new polymer based triangular shaped splitter can work simultaneously in broader spectrum, the only condition would be that the waveguides are single-mode guiding. It practically means that, what concerns communication wavelengths, it can on principle simultaneously operate at two mainly used wavelengths, 1310 and 1550 nm.
Design of the Novel Wavelength Triplexer Using Multiple Polymer Microring Resonators
V. Prajzler,E. Strilek,J. Spirkova,V. Jerabek
Radioengineering , 2012,
Abstract: We report about new design of wavelength triplexer using multiple polymer optical microring resonators. Triplexer consists of two downstream wavelength channels operating at 1490 ± 10 nm, 1555 ± 10 nm and one upstream wavelength channel operating at 1310 ± 50 nm. The parallel coupled double ring resonator was used for separation of the optical signal band at 1555 nm and filtered out signal bands 1310 nm and 1490 nm. The serially coupled triple optical microring resonator was used for separation of the optical signal band at 1490 nm and filtered out signal bands 1310 nm and 1555 nm. The design was done by using FullWAVETM software by the finite-difference time-domain method. Simulation showed that optical losses for band at 1555 nm were -3 dB and crosstalk between signal bands 1555 nm and 1490 nm was 24 dB. Calculated optical losses for channel 1490 nm were less than -2.5 dB and signal bands at 1555 nm was filtered out with less than 18 dB loss. The bands at 1310 nm were fully filtered out from both downstream wavelength channels operating at bands 1490 nm and 1555 nm.
Design, Fabrication and Properties of the Multimode Polymer Planar 1 x 2 Y Optical Splitter
V. Prajzler,N.K. Pham,J. Spirkova
Radioengineering , 2012,
Abstract: We report about design, fabrication and measurement of the properties of multimode 1 x 2 optical planar power splitter. The splitters were designed with help of OptiCAD software using ray tracing method. The dimensions of the splitters were then optimized for connecting standard Plastic Optical Fiber. Norland Optical Adhesives glues were used as optical waveguide layers and the design structures were completed by CNC engraving on Poly(methyl methacrylate) or Poly(methylmethacrylimide) substrate. The devices have the insertion loss around 7.6 dB at 650 nm and the coupling ratio was 52:48.
Design, Fabrication and Properties of Rib Poly(methylmethacrylimide) Optical Waveguides
V. Prajzler,J. Klapuch,O. Lyutakov,I. Huttel
Radioengineering , 2011,
Abstract: We report about design, fabrication and properties of the polymer optical waveguides deposited on silica-on-silicon substrate. The design of the waveguides is based on a concept that geometric dimensions of the single mode polymer waveguide are determined by geometrical parameters of the silica layer. The design of the waveguides was schemed for 650 nm, 850 nm, 1310 nm and 1550 nm wavelength. The design of the presented planar waveguides was realized on the bases of modified dispersion equation while the ridge waveguides design was proposed following the Fischbeck concept. Both designs were refined applying RSoft software using beam propagation method. Proposed shapes of the waveguides were etched by standard photolithography process into the silica layers and polymer waveguide layers were subsequently deposited into the treated substrate by spin coating. Poly(methylmethacrylimide) was used as the waveguide core material and polymethylmethacrylate was used as a cover protection layer. Propagation optical loss measurements were done by using the cut-back method and the best samples had optical losses lower than 0.6 dB/cm at 650 nm, 1310 nm and 1550 nm.
Design of Polymer Wavelength Splitter 1310 nm/1550 nm Based on Multimode Interferences
V. Prajzler,O. Lyutakov,I. Huttel,J. Spirkova
Radioengineering , 2010,
Abstract: We report about design of 1x2 1310/1550 nm optical wavelength division multiplexer based on polymer waveguides. The polymer splitter was designed by using RSoft software based on beam propagation method. Epoxy novolak resin polymer was used as core waveguides layer, silicon substrate with silica layer was used as buffer layer and polymethylmethacrylate was used as protection cover layer. The simulation shows that the output energy for the fundamental mode is 67.1 % for 1310 nm and 67.8 % for 1550 nm wavelength.
Hybrid Microoptical WDM Receiver for PON Communication
Vitezslav Jerabek,Julio Armas,Vaclav Prajzler
Advances in Electrical and Electronic Engineering , 2012,
Abstract: The paper presents the design, simulation and construction results of the wavelength division multiplex (WDM) optical hybrid receiver module for the passive optical network (PON). The optical WDM receiver was constructed using system of three micromodules in the new circle topology. The optical micromodule contains multimode fiber pigtail 50/125 μm, VHGT filter with collimation lens and two microwave optoelectronics receiver micromodules (OE receiver micromodules). OE receiver micromodules were designed by use small signal equivalent electrical circuit model and noise model, from which the mathematically solved the transmittance function, which was used for calculation and simulation of the optimal frequency characteristics and signal to noise ratio. For determine the limit frequency of OE receiver micromodule, the transcendent equation with transmittance function was numerically solved. OE receiver micromodule was composed of decollimation lenses and microwave optoelectronics receivers with bandwidth 2,5 GHz and alternatively in SMD technology with bandwidth 1,25 GHz, using the thin layer hybrid technology. WDM receiver use radiation 1490 nm for internet and 1550 nm for digital TV signals download information.
Nonsmooth Optimization Algorithms in Some Problems of Fracture Dynamics  [PDF]
V. V. Zozulya
Intelligent Information Management (IIM) , 2010, DOI: 10.4236/iim.2010.211073
Abstract: Mathematical statement of elastodynamic contact problem for cracked body with considering unilateral restrictions and friction of the crack faces is done in classical and weak forms. Different variational formulations of unilateral contact problems with friction based on boundary variational principle are considered. Nonsmooth optimization algorithms of Udzawa’s type for solution of unilateral contact problem with friction have been developed. Convergence of the proposed algorithms has been studied numerically.
Precessing Ball Solitons as Self-Organizing Systems during a Phase Transition in a Ferromagnet  [PDF]
V. V. Nietz
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.410A3010
Abstract:

Precessing ball solitons (PBS) in a ferromagnet during the first order phase transition is induced by a magnetic field directed along the axis of anisotropy, while the action of the periodic field perpendicular to the main magnetic field has been analyzed. Under these conditions, the characteristics of arising equilibrium PBS are uniquely determined by the frequency of the periodic field, but the solitons with other frequencies are impossible. For such structure, the entropy increase connected with dissipation is compensated by the decrease of the entropy due to the external periodic field. It is shown that the equilibrium PBS are essentially the “self-organizing systems” that can arise spotaneously in a metastable state of ferromagnet.

Movement of Self-Organizing Solitons in Ferromagnet  [PDF]
V. V. Nietz
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.610155
Abstract: Precessing ball solitons (PBS) in a ferromagnet during the first order phase transition induced by a magnetic field directed along the axis of anisotropy, while the additional action of high-frequency field perpendicular to the main magnetic field, are analyzed. It is shown that the spatial motion of solitons, associated with thermal fluctuations in the crystal, does not destroy the equilibrium of self-organized PBS.
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