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Passively mode-locked erbium doped fiber ring laser is investigated. We present laser configuration where nonlinear polarization rotation is used for modes synchronization. More than 32 nm output spectrum was obtained. Pulses repetition frequency stability and its temperature dependence is discussed and measured.
We report about a novel Laser-Doppler velocity profile sensor with high spatial resolution in the micrometer range. The sensor can be used for applications in fluid mechanics, e.g. flow measurements. Miniaturized sensors are often necessary to measure outside the laboratory. One approach utilizes a diffractive optical element (DOE) in order to reduce the number of optical elements. Another approach...
In this paper the effect of strain relaxation on the structural and optical properties of lattice mismatched InGaAs/GaAs heterostructures has been studied by means of X-ray diffractometry and photoreflectance spectroscopy. X-ray diffractometry reveals anisotropic strain relaxation, related to asymmetry in the formation of misfit dislocations, causing distortion of the epilayer unit cell and lowering...
Slow- and fast-light is the control of the velocity of light in a medium by light. As a fascinating new field in physics there is a fundamental interest on this effect on the one side, but on the other side there exist a lot of practical applications for telecommunication and information systems. Among these are optical signal processing, the radio frequency-photonics, nonlinear optics and spectroscopy...
The phase synchronization (phase-locking) of two lasers occurs in generating the same frequency (they can differ only in phase). The phase-locking effect can by forced by mutual radiation coupling between lasers. We investigated experimentally that phenomenon in two erbium doped ring fibre lasers. They were strongly coupled by using a 50/50 fibre coupler. Both lasers had the same resonator lengths...
POFs (polymer optical fibers) replace traditional communication media such as copper and glass step by step within short distance communication systems, mostly because of their cost-effectiveness and easy handling. POFs are used in various fields of optical communication, e.g. the automotive sector or in-house communication. The current "state of the art" are single mode communication systems...
This paper presents the design and fabrication of a waveguide in silicon using traditional microfabrication and manufacturing processes. Integrated waveguide has become important owing to the need for faster computing and the problems associated with copper as technology scales into the nanometer regime. Furthermore, photonic on-chip interconnect offers better latency, higher bandwidth capacity, power...
In this paper, a vertical pin-modulator is described, which replaces the standard backside mirror of the external cavity in a Littman-type laser system. By controlling the reflectivity of the pin-modulator the power of the output beam can be modulated. A pin-modulator with a reflectance contrast of about 4 dB leads to a contrast of more than 22 dB of the output power in the laser system. By using...
This work presents the analysis of photoluminescence effect in TiO2 matrix doped with Eu and Nd. Thin films were prepared by high energy reactive magnetron sputtering (HE RMS) method using metallic Ti-Eu and Ti-Nd mosaic targets and deposited on Si and SiO2. After deposition selected films were additionally annealed in an air ambient at 400degC and 600degC. The results of photoluminescence (PL) and...
The implementation of waveguides in thin glass foils results in graded index multimode waveguides. The paper presents two numerical approaches for modeling signal propagation within such waveguides.
Thin-film Cu(In,Ga)Se2 (CIGS) and CdTe photovoltaic (PV) modules have the potential to become competitive to silicon PV modules both in terms of their performance as well as productions costs. However, despite of many years of investigating them, some physical processes are not well-understood yet. One of the tools which may help to discover some of these process are numerical simulations with use...
Doping of TiO2 with various metal ions can modify its different properties. In this work, structural properties of transparent Tb-doped TiO2 thin films have been outlined. Thin films were deposited by high energy reactive magnetron sputtering (HE RMS) from metallic Ti-Tb target on Si and SiO2 substrates. Thin films were investigated by means of energy disperse spectrometry (EDS), X-ray diffraction...
The indium tin oxide and europium doped and undoped tin dioxide nanoparticles where synthesized by modified Pechini method. The powder X-ray diffraction (XRD) and transmission electro-microscopy (TEM) analyses where done in order to determined the structure and morphology of obtained materials. To determine the optical and electrical properties of the samples on the base of obtained powders thin films...
High temperature gallium nitride (HT-GaN) layers were grown by HVPE (hydride vapor phase epitaxy) method on low temperature GaN (LT-GaN) buffer layers deposited by HVPE or MOVPE method and on double MOVPE LT-GaN/AIN buffers. The (0001) sapphire substrates were applied. The HCl flow rate and deposition time intervals of nucleation layer deposition were varied in the range of 8-10 ml/min and 5-9 min...
The following topics are dealt with: integrated silicon waveguide; lattice mismatched InGaAs/GaAs heterostructures; laser-Doppler velocity profile sensors; phosphors; atomic force microscope; passively mode-locked fiber ring laser; solar cells; and transparent thin films.
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