Hybrid microoptical WDM receiver for PON communication

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

Design and modeling of the ENR polymer microring resonators add/drop filter for wavelength division multiplexing

We report about design, modeling, fabrication and properties of the polymer optical microring resonator. First step was to design single mode optical polymer ridge waveguides by using BeamPROPTM software and then optical polymer microring resonator was designed by using FullWAVETM software. The design of the single mode waveguides was done for the operating wavelengths 650 nm and 1550 nm. The design of the microring resonators was done for operating wavelength 1550 nm and for elimination wavelength 1490 nm. The resonator was designed on the bases of optical polymer waveguides Epoxy Novolak Resin deposited onto silica-on-silicon substrate. We used Polymethylmethacrylate as cover layers, or eventually, no cover layer was applied. Deposition tests of the designed structures were done by using standard photolithography process and electron lithography process. Surface qualities of the fabricated samples were checked using optical microscope (Olympus DX60) and waveguiding properties were examined by Metricon 2010 prism-coupler system

Design and investigation of properties of nanocrystalline diamond optical planar waveguides

Diamond thin films have remarkable properties comparable with natural diamond. Because of these properties it is a very promising material for many various applications (sensors, heat sink, optical mirrors, chemical and radiation wear, cold cathodes, tissue engineering, etc.) In this paper we report about design, deposition and measurement of properties of optical planar waveguides fabricated from nanocrystalline diamond thin films. The nanocrystalline diamond planar waveguide was deposited by microwave plasma enhanced chemical vapor deposition and the structure of the deposited film was studied by scanning electron microscopy and Raman spectroscopy. The design of the presented planar waveguides was realized on the bases of modified dispersion equation and was schemed for 632.8 nm, 964 nm, 1 310 nm and 1 550 nm wavelengths. Waveguiding properties were examined by prism coupling technique and it was found that the diamond based planar optical element guided one fundamental mode for all measured wavelengths. Values of the refractive indices of our NCD thin film measured at various wavelengths were almost the same as those of natural diamond

Optické vlastnosti epoxydové pryskyřice dotované ionty vlastních zemin

Příspěvek popisuje vlastnosti polymerních vrstev s dotací vzácných zemin. Polymer epoxidové pryskyřice Epoxy Novolak Resin byl dotován erbiem, erbiem/ytterbiem a dysprosiem. Tyto vrstvy byly připraveny metodou rotačního lití na křemíkové substráty a na substráty z křemenného skla. U vrstev byla studována infračervená spektra (IČ), absorpční spektra a luminiscenční spektra. IČ spektra prokázala, že polymerní vrstvy s obsahem vzácných zemin obsahují O-H pásy. Absorpční spektra byla použita pro zjištění pásů, které odpovídají pásům vzácných zemin, a luminiscenční spektra byla použita pro měření luminiscence erbia a erbia/ytterbia na vlnové délce kolem 1530 nm a pro luminiscenci dysprosia kolem vlnové délky 1300 nm. Ytterbium bylo použito jako syntetizér pro polymerní vrstvy s dotací erbia jako prostředek k dosažení větší intenzity optického záření na vlnové délce 1530 nm při optickém čerpání na vlnové délce 980 nm.The paper deals with the properties of rare earth ions doped polymer layers. Polymer Epoxy Novolak Resin was doped with erbium, erbium/ytterbium and dysprosium ions. The layers were fabricated by spin-coating on silicon and quartz substrates. We have investigated infrared (IR) spectra, absorption spectra and photoluminescence spectra. IR spectra show, that polymer layers doped with rare earth ions contain the O-H group. Absorption spectra were used for the investigation of bands corresponding to rare earth ions and photoluminescence measurements were used for the investigation of erbium and erbium/ytterbium luminescence around wavelength 1530 nm and for dysprosium around 1300 nm. Ytterbium ions were used as synthesizers for polymer layers doped with erbium to achieve higher photoluminescence intensity around wavelength 1530 nm

Waveguide Bragg Grating Filters Made from Optical Polymers

We report about the planar optical waveguide with a diffraction Bragg grating made in an optical polymer, which exhibits filter function useable for Passive Optical Network Fiber to the Home (PON FTTH) and sensor components. There were designed two topological and technological variants of an optical waveguide grating structures. The distribution of optical field and topological constants of waveguide grating was calculated and simulated by RSoft’s BeamPROP and GratingMode programs. The influence of topological parameters of waveguide grating filters like grating groove depth, waveguide layer thickness, length of the grating, etc. on key characteristic properties of the diffraction grating filter including diffraction efficiency, the central reflected wavelength, the bandwidth at 50% of the maximum transmission for guided modes and insertion losses were mainly investigated. Subsequently, structural parameters were optimized with respect to used fabrication methods

Design and construction of a WDM transceiver with VHGT using hybrid integration technology

We report about design and construction of WDM bidirectional transceiver module (TRx) for the passive optical network (PON) of a fiber to the home FTTH topology. The TRx uses a microoptics hybrid integration technology with volume holographic Bragg grating triplex filter (VHGT) and a collimation lenses for wavelength multiplexing/ demultiplexing. Our optical WDM transceiver TRx has been constructed using system of a four micromodules in the new circle topology. The optical micromodul with VHGT filter, two optoelectronic receivers’ micromodules for receiving download information (internet and digital TV signals) and optoelectronic transmitter micromodul for transmitting of a upload information

Design, Fabrication and Measurement Polymethylmethacrylate Optical Waveguides Prepared by Modification of Surface Profile by Applying Electric Field

In this paper, we describe results of our recent experiments on electric field preparation of the optical waveguides on PMMA films, their calculation and measurements. Planar PMMA films were prepared on Si/SiO2 wafers and measured using waveguiding technique. Micro-sized patterns were created on thin PMMA films by the effect of external electric field, perpendicular to the film surface. Waveguiding properties of prepared structures were checked by fitting optical fibre connected to laser light source. Optical losses of the farbicated channel waveguides were measured by using the cut-back method at wavelength 650 nm and output field was obtained by beam propagation analyzer BP104IR. Properties of the PMMA layers were simulated by beam propagation method by using BeamProp module from RSoft software

Design and modeling of the ENR polymer microring resonators add/drop filter for wavelength division multiplexing

We report about design, modeling, fabrication and properties of the polymer optical microring resonator. First step was to design single mode optical polymer ridge waveguides by using BeamPROPTM software and then optical polymer microring resonator was designed by using FullWAVETM software. The design of the single mode waveguides was done for the operating wavelengths 650 nm and 1550 nm. The design of the microring resonators was done for operating wavelength 1550 nm and for elimination wavelength 1490 nm. The resonator was designed on the bases of optical polymer waveguides Epoxy Novolak Resin deposited onto silica-on-silicon substrate. We used Polymethylmethacrylate as cover layers, or eventually, no cover layer was applied. Deposition tests of the designed structures were done by using standard photolithography process and electron lithography process. Surface qualities of the fabricated samples were checked using optical microscope (Olympus DX60) and waveguiding properties were examined by Metricon 2010 prism-coupler system

Influence of Optic Cable Construction Parts on Recovery Process after Gamma Irradiation

Fibre optic cables are widely used as communication cables in Instrumentation and Control (I&C) systems. In the case of nuclear power plants (NPPs), using optic cables in mild environments outside of containment areas are very common. However, at present, there is a need for fibre optic cables to be used in containment areas, i.e., with radiation. An optical fibre consists of a highly transparent core that possesses a higher refractive index than the surrounding transparent cladding, which possesses a lower refractive index. Most optical fibres are manufactured from glass (silica with required dopants) which is created at high temperatures from the reaction between gasses. The glass used in optical fibres is sensitive; it becomes dark during exposure to radiation, which compromises the optic functions. That is why there has been a slow infiltration of optic cable in NPP containment areas. Radiation resistant optic fibres have been developed. Although these fibres are called “radiation resistant,” they go through a darkening process (absorbance increase) as well, but not as quickly. Immediately after the irradiation has stopped, a recovery process starts in the glass structure. During this period, optical losses of the glass improve, but not to the original level as before the irradiation. During the testing of optic cables for the installation in nuclear power plant containment areas, we observed an unusual recovery process. In the beginning, a healing effect was observed. However, after a few days of recovery, the healing process stopped, and the trend changed again as a worsening of the optical properties was observed. This paper describes experiments which explain the reasons for such an unexpected behaviour