A generic methodology for constructing complex integrated electro-optic circuits in waveguided configurations is presented. The method is based on combining two techniques, 'laser ablation' and 'refractive index engineering by ion implantations.' The constructed circuits are side-cladded by air trenches that were produced using laser ablation and bottom-cladded by a layer with a reduced refractive index which is generated through the implantation of He.sup.+ ions. This fabrication technique enables the construction of circular structures with complex geometry featuring small radii of curvature, and further can be employed to construct microfluidic channels on the same substrate. The research demonstrates waveguides in both linear and circular configurations that were constructed in a potassium lithium tantalate niobate (KLTN) substrate using the aforementioned method, proving that this substrate is a suitable candidate for use in creating laboratories-on-a-chip with multifunctional capabilities. The proposed techniques used in the research are generic and applicable to a wide range of substrates.
We demonstrate tunable electro-optic guiding, shaping, and switching of beams in the near infrared spectrum ( 980 nm), typical of VCSEL technology, using biomimetic 3D funnel waveguides miniaturized into a sample of potassium–lithium–tantalate–niobate. The switchable waveguides are written using the slow photorefractive build-up of a 3D volume space-charge field caused by a diffracting continuous wave low intensity λ = 532 nm beam, and electro-optic functionality is supported by the quadratic electro-optic effect of the high-symmetry paraelectric phase. [ABSTRACT FROM AUTHOR]Copyright of Journal of Optics is the property of IOP Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Accession Number: 102282746; J Parravicini 1,2; Email Address: jacopo.parravicini@roma1.infn.it F Di Mei 1,3 D Pierangeli 1 A J Agranat 4 E DelRe 1,2; Affiliation: 1: Dipartimento di Fisica, ‘Sapienza’ Università di Roma, I-00185 Roma, Italy 2: IPCF-CNR, ‘Sapienza’ Università Roma, I-00185 Roma, Italy 3: Center for Life Nano Science Sapienza, Istituto Italiano di Tecnologia, I-00161 Roma, Italy 4: Applied Physics Department, Hebrew University of Jerusalem, IL-91904 Israel; Source Info: May2015, Vol. 17 Issue 5, p1; Subject Term: MINIATURE electronic equipment; Subject Term: ELECTRO-optical modulation; Subject Term: PHOTOREFRACTIVE effect; Subject Term: BIOMIMETIC materials; Subject Term: SURFACE emitting lasers; Subject Term: NEAR infrared spectroscopy; Number of Pages: 1p; Document Type: Article
We report the observation of diffraction cancellation for visible beams with widths from tens of wavelengths down to fractions of the optical wavelength. The phenomenon is observed at the transition from diffraction- to antidiffraction-dominated beam propagation, triggered by a thermal shock in a photorefractive nanodisordered lithium-enriched potassium-tantalate-niobate (KTN:Li) crystal. Here beams propagate without distortion, independently of intensity and size. Confirming the main prediction of the scale-free-optics model, we find a single unified light behavior that spans across the entire hierarchy of standard optical spatial scales, from wide plane-wave-like beams that obey geometrical optics down to ultranarrow beams with widths of the order of a single wavelength. [ABSTRACT FROM AUTHOR]Copyright of Physical Review A: Atomic, Molecular & Optical Physics is the property of American Physical Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Accession Number: 108999818; Di Mei, F. 1,2 Pierangeli, D. 1 Parravicini, J. 1 Conti, C. 1,3 Agranat, A. J. 4 DelRe, E. 1,3; Email Address:
eugenio.delre@uniroma1.it; Affiliation: 1: Dipartimento di Fisica, Università di Roma "La Sapienza," 00185 Rome, Italy 2: Center for Life Nanoscience, Sapienza, Istituto Italiano di Tecnologia, 00161 Rome, Italy 3: ISC-CNR, Università di Roma "La Sapienza," 00185 Rome, Italy 4: Brojde Center for Innovative Engineering and Computer Science, Hebrew University, Jeruslaem 91904, Israel; Source Info: Jul2015, Vol. 92 Issue 1-B, p1; Subject Term: SCALE-free network (Statistical physics); Subject Term: WAVELENGTHS; Subject Term: OPTICAL diffraction; Subject Term: OBSERVATION (Scientific method); Subject Term: PHOTOREFRACTIVE effect; Number of Pages: 5p; Document Type: Article
A method for suppressing the formation of optical damage in quadratic electrooptic devices operated at short wavelengths is presented. Formation of optical damage is attributed to the generation of a trapped space charge induced by photoionization of impurity ions by the propagating beam. It is shown that in potassium lithium tantalate niobate where the electrooptic effect is quadratic, operating the electrooptic device by a bipolar driving voltage prevents the space charge from accumulating, which inhibits the formation of the optical damage. A 6 hours continuous operation of electrooptic modulator for a 30 W/cm2 at λ = 445 nm input beam is demonstrated.
Rogue waves are observed as light propagates in the extreme nonlinear regime that occurs when a photorefractive ferroelectric crystal is undergoing a structural phase transition. The transmitted spatial light distribution contains bright localized spots of anomalously large intensity that follow a signature long-tail statistics that disappears as the nonlinearity is weakened. The isolated wave events form as out-of-equilibrium response and disorder enhance the Kerr-saturated nonlinearity at the critical point. Self-similarity associable to the individual observed filaments and numerical simulations of the generalized nonlinear Schrodinger equation suggests that dynamics of soliton fusions and scale invariance can microscopically play an important role in the observed rogue intensities and statistics.
Accession Number: edselc.2-52.0-84940688543; (Physical Review Letters, 25 August 2015, 115(9)) Publication Type: Academic Journal; Rights: Copyright 2015 Elsevier B.V., All rights reserved.
Accession Number: edselc.2-52.0-84926333767; (Nature Photonics, 31 March 2015, 9(4):228-232) Publication Type: Academic Journal; Rights: Copyright 2015 Elsevier B.V., All rights reserved.
We demonstrate the integration of a miniaturized 30(x) μm×30(y) μm×2.7(z) mm electro-optic phase modulator operating in the near-IR (λ=980 nm) based on the electro-activation of a funnel waveguide inside a paraelectric sample of photorefractive potassium lithium tantalate niobate. The modulator forms a basic tassel in the realization of miniaturized reconfigurable optical circuits embedded in a single solid-state three-dimensional chip.;
Accession Number: 25831339. Language: English. Date Created: 20150402. Update Code: 20150402. Publication Type: Journal Article. Journal ID: 7708433. Publication Model: Print. Cited Medium: Internet. NLM ISO Abbr: Opt Lett. Linking ISSN: 01469592. Subset: In-Data-Review; IM; Date of Electronic Publication: 20150401. ; Original Imprints: Publication: New York, Optical Society of America.
