227 research outputs found
Arrayed-waveguide-grating light collector for on-chip spectroscopy
We present a novel arrayed-waveguide-grating (AWG) device with improved external (biomedical) signal collection for use in on-chip spectroscopy. The collection efficiency of the device is compared to that of a standard AWG. We also present experimental results on the collection efficiency and size of the collection volume
Northernmost occurrence of Hemiramphus far (Actinopterygii: Hemiramphidae) in the Aegean Sea
A new record of Hemiramphus far from the northern Aegean Sea is presented, based on a single specimen collected off Eski Foça shores, Turkey. Further individuals were observed (but not collected) in the same area, indicating an established population
Integrated AWG spectrometer for on-chip optical coherence tomography and Raman spectroscopy
Silicon oxynitride-based arrayed waveguide grating (AWG) spectrometers were designed for on-chip spectral-domain optical coherence tomography (OCT) systems and Raman spectroscopy of the skin. A novel geometrical layout for Raman spectroscopy was introduced to reduce loss. Measurements show that integrated optics has a good potential for miniaturizing current OCT systems
Electro-Optic and Electro-absorption characterization of InAs quantum dot waveguides
Cataloged from PDF version of article.Abstract
Optical properties of multilayer InAs quantum dot waveguides, grown by molecular beam epitaxy, have been studied under applied electric field. Fabry-Perot measurements at 1515 nm on InAs/GaAs quantum dot structures yield a significantly enhanced linear electro-optic efficiency compared to bulk GaAs. Electro-absorption measurements at 1300 nm showed increased absorption with applied field accompanied with red shift of the spectra. Spectral shifts of up to 21% under 18 Volt bias was observed at 1320 nm. (C) 2008 Optical Society of America
Study of Digital Competence of the Students and Teachers in Ukraine
Professional fulfillment of the personality at the conditions of the digital economy requires the high level of digital competency. One of the ways to develop these competencies is education. However, to provide the implementation of digital education at a high level, the digital competency of the teachers and students is a must. This paper presents explanations on the level determination of the digital competencies for teachers and students in Ukraine according to the DigComp recommendations. We tried to identify the main factors that reflect the degree of readiness teachers and students for digital education based on their self-evaluation. We also attempted to estimate the level of digital competencies based on the analysis of Case-Studies execution results. The complex analysis let us assess the connection between respondents’ self-evaluation and their real competencies. Here we provide a methodology and a model of level competencies determination by means of a survey, expert case rating and the results of the statistical analysis. On the basis of the obtained results, this paper suggests further research prospects and recommendations on the digital competency development in educational institutions in Ukraine
Modulation of multilayer InAs quantum dot waveguides under applied electric field
Electric field dependence of optical modulation in self assembled InAs quantum dot waveguides have been studied at 1300 and 1500 nm. Electro-absorption and electro-optic coefficients of these waveguides have been obtained at both wavelengths. © 2007 Optical Society of America
Modulation in InAs quantum dot waveguides
Modulation in molecular beam epitaxy grown self-assembled InAs quantum dot waveguides have been studied at 1500 nm as a function of wavelength and voltage. Enhanced electro-optic coefficients compared to bulk GaAs were observed. © 2007 Optical Society of America
Electro-optic modulation of InAs quantum dot waveguides
The linear electro-optic properties in waveguides containing self-organized In As quantum dots were studied experimentally. Fabry-Perot measurements at 1515 nm on InAs/GaAs quantum dot structures yield a significantly enhanced linear electro-optic efficiency compared to bulk GaAs
- …