We demonstrate an electro-optic response that is linear in the amplitude but independent of the sign of the applied electric field. The symmetry-preserving linear electro-optic effect emerges at low applied electric fields in freezing nanodisordered KNTN above the dielectric peak temperature, deep into the nominal paraelectric phase. Strong temperature dependence allows us to attribute the phenomenon to an anomalously reduced thermal agitation in the reorientational response of the underlying polar-nanoregions. (C) 2014 Optical Society of America
Anti-diffraction is a theoretically predicted nonlinear optical phenomenon that occurs when a light beam spontaneously focalizes independently of its intensity. We observe anti-diffracting beams supported by the peak-intensity-independent diffusive nonlinearity that are able to shrink below their diffraction-limited size in photorefractive lithium-enriched potassium-tantalate-niobate (KTN:Li).;
Accession Number: 25607093. Language: English. Date Created: 20150122. Date Completed: 20150512. Update Code: 20150512. Publication Type: Journal Article. Journal ID: 101137103. Publication Model: Print. Cited Medium: Internet. NLM ISO Abbr: Opt Express. Linking ISSN: 10944087. Subset: PubMed-not-MEDLINE; Date of Electronic Publication: 20141215. ; Original Imprints: Publication: Washington, DC : Optical Society of America, 1997-
The upper part of the human eccrine sweat ducts, embedded within the epidermis layer, have a well-defined helical structure. It was recently suggested that, as electromagnetic entities, the sweat ducts interact with sub-mm waves [Y. Feldman et al., Phys. Rev. Lett. 100, 128102 (2008)]. Although correlation between changes in the reflectance spectrum in this frequency range and physiological activities has been shown, a direct link between the electromagnetic reflection and the helical structure itself has remained to be established. The fact that the sweat ducts manifest natural homochirality is henceforth used to produce this link. We report the detection of circular polarization asymmetry in the electromagnetic reflection from the human skin at sub-THz frequencies in vivo. We compare the results to numerical simulations and to measurements of a fabricated metamaterial. We argue that the observed circular dichroism can be interpreted uniquely as the signature of the helical structure itself. By twisting reflected electromagnetic waves, the human skin exhibits properties which are usually discussed only in the framework of metamaterial science.;
Accession Number: 24827286. Language: English. Date Created: 20140515. Date Completed: 20150415. Update Code: 20150415. Publication Type: Journal Article. Journal ID: 101136452. Publication Model: Print-Electronic. Cited Medium: Internet. NLM ISO Abbr: Phys Rev E Stat Nonlin Soft Matter Phys. Linking ISSN: 15393755. Subset: IM; Date of Electronic Publication: 2014 Apr 25. ; Original Imprints: Publication: Melville, NY : Published by the American Physical Society through the American Institute of Physics, c2001-
Item Citation: The European Physical Journal B - Condensed Matter and Complex Systems. July 2014, Vol. 87 Issue 7Accession Number: edsgcl.386613351; Publication Type: Academic Journal; Source: The European Physical Journal B - Condensed Matter and Complex Systems; Language: English; Publication Date: 20140701; Rights: Copyright 2014 Gale, Cengage Learning. All rights reserved.; Imprint: Springer
J Parravicini, M Brambilla, L Columbo, F Prati, C Rizza, G Tissoni, AJ Agranat, and E DelRe. 2014. “
Observation of electro-activated localized structures in broad area VCSELs..” Optics Express, 22, 24, Pp. 30225 - 30233.
Publisher's Version Abstract We demonstrate experimentally the electro-activation of a localized optical structure in a coherently driven broad-area vertical-cavity surface-emitting laser (VCSEL) operated below threshold. Control is achieved by electro-optically steering a writing beam through a pre-programmable switch based on a photorefractive funnel waveguide.;
Accession Number: 25606953. Language: English. Date Created: 20150122. Update Code: 20150317. Publication Type: Journal Article. Journal ID: 101137103. Publication Model: Print. Cited Medium: Internet. NLM ISO Abbr: Opt Express. Linking ISSN: 10944087. Subset: In-Process; IM; Date of Electronic Publication: 20141201. ; Original Imprints: Publication: Washington, DC : Optical Society of America, 1997-
Electro-optically tunable transmission grating was imprinted in potassium lithium tantalate niobate by irreversible spatial patterning of the dielectric constant. While embedded into waveguided architecture, it provides a reliable and versatile building block for opto-electronic circuitry, capable of both active switching and multiplexing. Realization of such a block is critical for the fabrication of integrated photonic circuits in electro-optic substrates by means of Refractive Index Engineering by fast ion implantation.
Item Citation: Applied Physics B: Lasers and Optics. April 2014, Vol. 115 Issue 1, p143, 5 p.Accession Number: edsgcl.361133533; Publication Type: Academic Journal; Source: Applied Physics B: Lasers and Optics; Language: English; Publication Date: 20140401; Rights: Copyright 2014 Gale, Cengage Learning. All rights reserved., COPYRIGHT 2014 Springer; Imprint: Springer
We study the formation of 2D self-trapped beams in nanodisordered potassium-sodium-tantalate-niobate (KNTN) cooled below the dynamic glass transition. Supercooling is shown to accelerate the photorefractive response and enhance steady-state anisotropy. Effects in the excited state are attributed to the anomalous slim-loop polarization curve typical of relaxors dominated by non-interacting polar-nano-regions. (C) 2014 Optical Society of America
