Search results for "Reflection"

Optical properties of the low-molecular amorphous azochromophores and their application in holography

2015

The films based on the low-molecular amorphous azochromophore 2-(3-(4-((4- (Ethyl(2-(trityloxy)ethyl)amino)phenyl)diazenyl)styryl)-5,5-dimethylcyclohex-2-enylidene) malononitrile (IWK-2M) were prepared. The optical properties of the material, such as transmittance and reflection spectra of the film, sensitivity to polarization holographic recording by two wavelengths (405 and 532 nm) were studied. The direct relief formation during the polarization holographic recording was explored, relief depth dependence on exposure and record beam intensity was investigated. The holographic matrix on this material base was produced without chemical etching process; the replication of holographic image w…

Refractometric sensor based on whispering-gallery modes of thin capillarie.

2009

Whispering-gallery modes resonances of submicron wall thickness capillaries exhibit very large wavelength shifts as a function of the refractive index of the medium that fills the inside. The sensitivity to refractive index changes is larger than in other optical microcavities as microspheres, microdisks and microrings. The outer surface where total internal reflection takes place remains always in air, enabling the measure of refractive index values higher than the refractive index of the capillary material. The fabrication of capillaries with submicron wall thickness has required the development of a specific technique. A refractometer with a response higher than 390 nm per refractive ind…

A Dialogical Exploration of Student Teacher Reflections: From Notions of Insideness and Outsideness to Pedagogical Alongsideness

2023

This article offers a dialogical exploration of student teachers’ reflections on notions of insideness and outsideness, the focal themes of an Erasmus+ ten-day intensive programme (IP). The arts-based, interdisciplinary IP involved 32 student participants and twelve members of staff from eight European universities hosted by the University of Jyväskylä, Finland. The data for this paper are based on the final written essays of student participants as they reflected on their understanding of outsideness and insideness at the end of the IP. The dialogic approach used in the analysis allows for a careful exploration of how the students attended to different experiences, surmised the meaning of …

Toward a Phenomenology-oriented Transformative Education in Adult Life

2021

The paper highlights Husserlian phenomenology as a fruitful pedagogical paradigm for adult education philosophy. Actually, through a comparison with the Transformative Learning approach as developed by Jack Mezirow, phenomenology is presented as providing a peculiar account on learning from experience as well as on reflection. More precisely, a stress on the value of reflection in adulthood is detected both in the Deweyan line of thought, as expressed by Mezirow, and in the Husserlian one, as developed also in Martin Heidegger, Hannah Arendt, and Paul Ricoeur. My aim is to show that, even though the reflective approach has certainly affected contemporary education, chiefly the phenomenologi…

Review and comparison of experimental techniques used for determination of thin film electro-optic coefficients

2015

The results of electro-optic coefficient measurements performed with three commonly applied techniques used to assess electro-optic coefficients: the Mach–Zehnder, the Teng–Man, and the attenuated total reflectance technique are reported. It is shown that the signal obtained by the Mach–Zehnder and Teng–Man techniques is strongly influenced by the multiple internal reflection and piezo- and electrostrictive thickness change effects, which in our opinion have not been addressed sufficiently in the literature. A novel approach based on using Abeles matrix formalism is implemented for the retrieval of electro-optic coefficients from experimental data. The measurement results, errors, and compa…

Hawking radiation of massive modes and undulations

2012

We compute the analogue Hawking radiation for modes which posses a small wave vector perpendicular to the horizon. For low frequencies, the resulting mass term induces a total reflection. This generates an extra mode mixing that occurs in the supersonic region, which cancels out the infrared divergence of the near horizon spectrum. As a result, the amplitude of the undulation (0-frequency wave with macroscopic amplitude) emitted in white hole flows now saturates at the linear level, unlike what was recently found in the massless case. In addition, we point out that the mass introduces a new type of undulation which is produced in black hole flows, and which is well described in the hydrodyn…

Interrogation of whispering-gallery modes resonances in cylindrical microcavities by backreflection detection

2009

The excitation of whispering-gallery-mode resonances of cylindrical microcavities, using narrow fiber tapers, produces simultaneously the excitation of spiral modes. The power coupled to the spiral modes leads to a significant broadening of the dips observed in the spectrum of light transmitted through the taper. We demonstrate that whispering-gallery modes resonances of cylindrical microcavities can also be interrogated by measuring the reflection spectrum. Unlike the dips observed in transmission, the peaks in the reflection spectrum are symmetric and narrower than the corresponding transmission dips.

SIRIPRO PROJECT: DEEP CRUSTAL SETTING IN THE NORTHERN SICILY CONTINENTAL MARGIN AND ITS ADJACENT ONSHORE

2009

Generalized Thru-Reflect-Line Calibration Technique for the Measurement of Multimodal Radiating Waveguides

2017

The objective of this letter is to extend the use of the generalized thru-reflect-line measurement technique to the case of a radiating multimodal rectangular waveguide aperture. Although this radiating aperture has been carefully studied from a theoretical point of view, the relevant experimental characterization has been limited to the case where the feeding waveguide is monomodal. In addition to theory, we also present experimental results that agree quite well with full-wave simulations, thereby fully validating the measurement technique.

Weak regularity and consecutive topologizations and regularizations of pretopologies

2009

Abstract L. Foged proved that a weakly regular topology on a countable set is regular. In terms of convergence theory, this means that the topological reflection Tξ of a regular pretopology ξ on a countable set is regular. It is proved that this still holds if ξ is a regular σ -compact pretopology. On the other hand, it is proved that for each n ω there is a (regular) pretopology ρ (on a set of cardinality c ) such that ( RT ) k ρ > ( RT ) n ρ for each k n and ( RT ) n ρ is a Hausdorff compact topology, where R is the reflector to regular pretopologies. It is also shown that there exists a regular pretopology of Hausdorff RT -order ⩾ ω 0 . Moreover, all these pretopologies have the property…