Search results for "Kerr"
showing 10 items of 494 documents
Experimental demonstration of phase bistability in a broad-area optical oscillator with injected signal
2015
We demonstrate experimentally that a broad-area laserlike optical oscillator (a nondegenerate photorefractive oscillator) with structured injected signal displays two-phase patterns. The technique [de Valc\'arcel and Staliunas, Phys. Rev. Lett. 105, 054101 (2010)] consists in spatially modulating the injection, so that its phase alternates periodically between two opposite values, i.e., differing by $\ensuremath{\pi}$.
Surface hysteresis curves of Fe(110) and Fe(100) crystals in ultrahigh vacuum — evidence of adsorbate influences
1992
Abstract We have investigated hysteresis curves of silicon-stabilized Fe(100) and Fe(110) crystals using Polarized Secondary Electron Emission (PSEE) for surface magnetization processes and Magneto-Optical Kerr Effect (MOKE) for bulk hysteresis curves. In particular, the influence of adsorbates (oxygen and sulphur) and surface roughness on the magnetization reversal has been studied. For surface hysteresis curves we found adsorbate-induced reductions of coercive force of up to 50%; the bulk hysteresis curves showed significantly smaller deviations. Similar changes were caused by surface disorder on an atomic scale induced by ion bombardment. The results agree qualitatively with a previous e…
All-optical signal processing at ultra-low powers in bottle microresonators using the Kerr effect.
2010
We present experimental results on nonlinear, ultra-low power photonics applications based on a silica whispering-gallery-mode microresonator. Our bottle microresonator combines an ultrahigh quality factor of Q10(8) with a small mode volume V. The resulting Q(2)/V-ratio is among the highest realized for optical microresonators and allows us to observe bistable behavior at very low powers. We report single-wavelength all-optical switching via the Kerr effect at a record-low threshold of 50 microW. Moreover, an advantageous mode geometry enables the coupling of two tapered fiber waveguides to a bottle mode in an add-drop configuration. This allows us to route a CW optical signal between both …
Opposite Ends: widows' narratives of contemporary late life
2020
The life course perspective frames this study of contemporary late life. Thematic narrative analysis is employed to analyse the stories of 16 Finnish widows aged 79–89 years (Moving in Old Age: Transitions in Housing and Care research project) in order to explore the experiences related to growing old. The results indicate two kinds of narratives: nostalgic reminiscences about a happy past are typical of the retiring to solitude story, characterised by experiences of life nearing its end and of letting go; and those inclined towards the keeping up narrative are still seeking new experiences and playing active roles in everyday life. Both kinds of stories encompass well-being, in spite of…
The more you move, the more action you construct : a motion capture study on head and upper-torso movements in constructed action in Finnish Sign Lan…
2020
Abstract This paper investigates, with the help of motion capture data processed on corpus principles, the characteristics of head and upper-torso movements in constructed action and regular narration (i.e., signing without constructed action) in FinSL. Specifically, the paper evaluates the validity of two arguments concerning constructed action: that constructed action forms a continuum with regular narration, and that constructed action divides into three subtypes (i.e., overt, reduced, and subtle). The results presented in the paper support the first argument but not directly the second one. Because of the ambiguous position of reduced constructed action in between subtle and overt const…
Narrative Tools for Games : Focalization, Granularity, and the Mode of Narration in Games
2015
This article looks at three narratological concepts—focalization, granularity, and the mode of narration—and explores how these concepts apply to games. It is shown how these concepts can be used as tools for creating meaning-effects, which are understood here as cognitive responses from the player. Focalization is shown to have a hybrid form in games. This article also explores the different types of narrators and granularities in games, and how these three concepts can be used to create meaning-effects. This is done by discussing examples from several games, for example, Assassin’s Creed III, Skyrim, Fallout: New Vegas, and Civilization.
Transnational Heritage in the Making. Strategies for Narrating Cultural Heritage as European in the Intergovernmental Initiative of the European Heri…
2014
The idea of a transnational cultural heritage has become topical in Europe because of the new EU heritage initiatives, such as the European Heritage Label scheme. Even though the scheme is administered at the European level, its implementation is transferred to heritage agents in the countries participating in the initiative. How do the heritage agents narrate the labeled heritage sites as European? Using the method of narrative analysis, this article identifies six key strategies of making sense of a European cultural heritage. Even though the scheme includes certain frameworks in which the heritage agents have to interpret and narrate the sites as European, it enables them to interpret th…
A liquid alkoxide precursor for the atomic layer deposition of aluminum oxide films
2020
For large-scale atomic layer deposition (ALD) of alumina, the most commonly used alkyl precursor trimethylaluminum poses safety issues due to its pyrophoric nature. In this work, the authors have investigated a liquid alkoxide, aluminum tri-sec-butoxide (ATSB), as a precursor for ALD deposition of alumina. ATSB is thermally stable and the liquid nature facilitates handling in a bubbler and potentially enables liquid injection toward upscaling. Both thermal and plasma enhanced ALD processes are investigated in a vacuum type reactor by using water, oxygen plasma, and water plasma as coreactants. All processes achieved ALD deposition at a growth rate of 1-1.4 angstrom/cycle for substrate tempe…
CH4 oxidation in a boreal lake during the development of hypolimnetic hypoxia
2020
AbstractFreshwater ecosystems represent a significant natural source of methane (CH4). CH4 produced through anaerobic decomposition of organic matter (OM) in lake sediment and water column can be either oxidized to carbon dioxide (CO2) by methanotrophic microbes or emitted to the atmosphere. While the role of CH4 oxidation as a CH4 sink is widely accepted, neither the magnitude nor the drivers behind CH4 oxidation are well constrained. In this study, we aimed to gain more specific insight into CH4 oxidation in the water column of a seasonally stratified, typical boreal lake, particularly under hypoxic conditions. We used 13CH4 incubations to determine the active CH4 oxidation sites and the …
Nonintrusive monitoring and quantitative analysis of strong laser-field-induced impulsive alignment
2004
We report the observation of impulsive alignment of $\mathrm{C}{\mathrm{O}}_{2}$ molecules produced through their interaction with a nonresonant, strong laser pulse. The periodic alignment is monitored using a polarization technique generally employed in optical Kerr effect experiments; the birefringence produced by alignment of the molecular sample is measured with a weak pulse, time-delayed with respect to the alignment pulse. The technique provides a signal proportional to $⟨{\mathrm{cos}}^{2}\phantom{\rule{0.2em}{0ex}}\ensuremath{\theta}⟩\ensuremath{-}\frac{1}{3}$, where $\ensuremath{\theta}$ is the polar angle between the molecular axis and the strong-field polarization axis. Experimen…