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Sub 5 nm

Cecilie S Granerød, Bjørn L Aarseth, Dan Phuong Nguyen, Calliope Bazioti, Alexander Azarov, Bengt Svensson, Lasse Vines, Øystein Prytz
Functionalizing transparent conducting oxides (TCOs) is an intriguing approach to expand the tunability and operation of optoelectronic devices. 
 For example, forming nanoparticles that act as quantum wells or barriers in zinc oxide (ZnO), one of the main TCOs today, may expand its optical and electronic tunability. In this work, 800~keV Ge ions have been implanted at a dose of 1· 10<sup>16</sup>cm<sup>-2</sup> into crystalline ZnO. After annealing at 1000 °C embedded disk-shaped particles with diameters up to 100 nm are formed...
February 11, 2019: Nanotechnology
Getnet K Tadesse, Wilhelm Eschen, Robert Klas, Maxim Tschernajew, Frederik Tuitje, Michael Steinert, Matthias Zilk, Vittoria Schuster, Michael Zürch, Thomas Pertsch, Christian Spielmann, Jens Limpert, Jan Rothhardt
Ptychography enables coherent diffractive imaging (CDI) of extended samples by raster scanning across the illuminating XUV/X-ray beam, thereby generalizing the unique advantages of CDI techniques. Table-top realizations of this method are urgently needed for many applications in sciences and industry. Previously, it was only possible to image features much larger than the illuminating wavelength with table-top ptychography although knife-edge tests suggested sub-wavelength resolution. However, most real-world imaging applications require resolving of the smallest and closely-spaced features of a sample in an extended field of view...
February 11, 2019: Scientific Reports
Yu Zhang, Yi-Chun Ling, Kaiqi Zhang, Cale Gentry, David Sadighi, Greg Whaley, James Colosimo, Paul Suni, S J Ben Yoo
This paper reports on large field-of-regard, high-efficiency, and large aperture active optical phased arrays (OPAs) for optical beam steering in LIDAR systems. The fabricated 5 mm-long silicon photonic OPA with a 1.3 μm waveguide pitch achieved adjacent waveguide crosstalk below -12dB. A relatively large and uniform emission aperture has been achieved with a low-contrast silicon nitride assisted grating (~20 dB/cm) whose emission profile can be further optimized using an apodized design. The fabricated silicon-photonic OPA demonstrated > 40° lateral beam steering with no sidelobes in a ± 33° field-of-regard and 3...
February 4, 2019: Optics Express
Rae Young Kim, Ho Ra
RATIONALE: Increases in cosmetic laser use have led to recent reports of accidental retinal injuries, most of which are limited to the posterior pole. We report a case of peripheral retinal injury caused by a 1064-nm Nd:YAG: neodymium-doped yttrium aluminum garnet. PATIENT CONCERNS: A 27-year-old Asian woman was admitted with scotoma symptoms in her right eye. The patient was a skin care technician. Three days before admission, a laser beam had struck her eye while she was preparing for a laser procedure...
February 2019: Medicine (Baltimore)
Ganesh Jayakumar, Mikael Östling
Silicon nanowires (SiNWs) are widely used technology for sensing applications. Complementary metal-oxide-semiconductor (CMOS) integration of SiNWs advances lab-on-chip (LOC) technology and offers opportunities for read-out circuit integration, selective and multiplexed detection. In this work, we propose novel scalable pixel based biosensors exploiting the integration of SiNWs with CMOS in fully-depleted silicon-on-insulator (FDSOI) technology. A detailed description of the wafer-scale fabrication of SiNW pixel using the CMOS compatible sidewall-transfer-lithography (STL) as an alternative to widely investigated time inefficient e-beam lithography is presented...
February 5, 2019: Nanotechnology
Ilya V Kubasov, Aleksandr M Kislyuk, Andrei V Turutin, Alexander S Bykov, Dmitry A Kiselev, Aleksandr A Temirov, Roman N Zhukov, Nikolai A Sobolev, Mikhail D Malinkovich, Yuriy N Parkhomenko
We present a low-frequency sensor for the detection of vibrations, with a sub-nm amplitude, based on a cantilever made of a single-crystalline lithium niobate (LiNbO₃) plate, with a bidomain ferroelectric structure. The sensitivity of the sensor-to-sinusoidal vibrational excitations was measured in terms of displacement as well as of acceleration amplitude. We show a linear behavior of the response, with the vibrational displacement amplitude in the entire studied frequency range up to 150 Hz. The sensitivity of the developed sensor varies from minimum values of 20 μV/nm and 7 V/ g (where g = 9...
February 1, 2019: Sensors
Qiancheng Zhao, Yanhua Luo, Yutang Dai, Gang-Ding Peng
The near-infrared luminescence of Bi-doped aluminosilicate fiber within pump wavelengths between 710 and 990 nm and under varying pump powers and operation temperatures has been investigated systematically. It is revealed that there exist two emission bands peaking around 1120 and at 1300 nm, which are believed to be associated with two different aluminum-related bismuth active centers (BAC-Al1 and BAC-Al2); the BAC-Al2 is found to be more efficiently excited at a lower temperature within the spectral range of 790-850 nm...
February 1, 2019: Optics Letters
Marco Kraft, Christian Wuerth, Emilia Palo, Tero Soukka, Ute Resch-Genger
We present here a systematic analysis of the influence of Tm<sup>3+</sup> doping concentrations (<i>x<sub>Tm</sub></i>) on the excitation power (<i>P</i>)-dependent upconversion luminescence and -performance of hexagonal-phase NaYF<sub>4</sub>: 20 % Yb<sup>3+</sup>, <i>x<sub>Tm</sub></i> % Tm<sup>3+</sup> upconversion nanoparticles (UCNPs) for <i>x<sub>Tm</sub></i> of 0...
January 28, 2019: Methods and Applications in Fluorescence
Hassan Mahmoudi, Maryam Pourhajibagher, Mohammad Yousef Alikhani, Abbas Bahador
PURPOSE: Burn patients are particularly susceptible to microbial infection. Staphylococcus aureus causes burn wound, impetigo and cellulitis. Although sub-lethal antimicrobial photodynamic therapy (aPDT) would not result in microorganism killing, it can considerably influence microbial virulence factor. METHODS: Twelve methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) isolated from burns patients. To determine the sub-lethal dose of aPDT, 12 clinical isolates of S...
January 23, 2019: Photodiagnosis and Photodynamic Therapy
William M Abbott, Christopher P Murray, Chuan Zhong, Christopher Smith, Cormac McGuinness, Ehsan Rezvani, Clive Downing, Dermot Daly, Amanda Petford-Long, Frank Bello, David McCloskey, John F Donegan
The use of a metallic adhesion layer is known to increase the thermo-mechanical stability of Au thin films against solid-state dewetting, but in turn results in damping of the plasmonic response, reducing their utility in applications such as heat-assisted magnetic recording (HAMR). In this work, 50 nm Au films with Ti adhesion layers ranging in thickness from 0.1 - 5 nm were fabricated, and their thermal stability, electrical resistivity, and plasmonic response were measured. Sub-nanometer adhesion layers are demonstrated to significantly increase the stability of the thin films against dewetting at elevated temperatures (>200oC), compared to standard adhesion layer thicknesses that are in the range of 2 - 5 nm...
January 25, 2019: ACS Applied Materials & Interfaces
Hye-Yeon Son, Mak-Soon Lee, Eugene Chang, Seog-Young Kim, Bori Kang, Hyunmi Ko, In-Hwan Kim, Qixin Zhong, Young-Hee Jo, Chong-Tai Kim, Yangha Kim
Due to poor water solubility and high susceptibility to chemical degradation, the applications of quercetin have been limited. This study investigated the effects of pH on the formation of quercetin-loaded nanoemulsion (NQ) and compared the hypocholesterolemic activity between quercetin and NQ to utilize the quercetin as functional food ingredient. NQ particle size exhibited a range of 207⁻289 nm with polydispersity index range (<0.47). The encapsulation efficiency increased stepwise from 56 to 92% as the pH increased from 4...
January 22, 2019: Nutrients
Prasoon Kumar Shandilya, Johannes E Froech, Matthew Mitchell, David P Lake, Sejeong Kim, Milos Toth, Bishnupada Behera, Chris Healey, Igor Aharonovich, Paul E Barclay
Hexagonal boron nitride (hBN) is an emerging layered material that plays a key role in a variety of two-dimensional devices, and has potential applications in nanophotonics and nanomechanics. Here, we demonstrate the first cavity optomechanical system incorporating hBN. Nanomechanical resonators consisting of hBN beams with dimensions of 13.5 um x 1.1 um x 31 nm were fabricated using electron beam induced etching and positioned in the optical nearfield of silicon microdisk cavities. The resulting cavity optomechanical system has sub-picometer/Hz^0...
January 24, 2019: Nano Letters
Kishor Chandra Kharkwal, Rachna Chaurasia, Ashim Kumar Pramanik
Here, we study an interface induced magnetic properties in 3$d$-5$d$ based superlattice made of La$_{0.67}$Sr$_{0.33}$MnO$_3$ and double perovskite Sr$_2$FeIrO$_6$, respectively. Bulk LSMO is metallic and shows ferromagnetic (FM) ordering above room temperature. In contrast, bulk SFIO is an antiferromagnet (AFM) with N$\acute{e}$el temperature around 45 K ($T_N$) and exhibits an insulating behavior. Two set of superlattices have been grown on SrTiO$_3$ (100) crystal with varying thickness of FM LSMO layer. Superlattice with equal thickness of La$_{0...
January 18, 2019: Journal of Physics. Condensed Matter: An Institute of Physics Journal
D R Moon, T Ingham, L K Whalley, P W Seakins, M T Baeza-Romero, D E Heard
The production of gas-phase hydroperoxyl radicals, HO2, is observed directly from sub-micron airborne TiO2 nanoparticles irradiated by 300-400 nm radiation. The rate of HO2 production as a function of O2 pressure follows Langmuir isotherm behaviour suggesting O2 is involved in the production of HO2 following its adsorption onto the surface of the TiO2 aerosol. Reduction of adsorbed O2 by photogenerated electrons is likely to be the initial step followed by reaction with a proton produced via oxidation of adsorbed water with a photogenerated hole...
January 18, 2019: Physical Chemistry Chemical Physics: PCCP
K Zhukovsky, A Kalitenko
The harmonic power and bunching evolution in X-ray single-pass free-electron lasers (FELs) is modelled and the harmonic generation in a phase-shifted two-frequency FEL is explored. The advanced phenomenological FEL model, which is validated numerically and experimentally, is employed. The model accounts for major losses for each harmonic individually; it is compared with reported experimental data and with PERSEO numerical simulations, which are performed here for a variety of experiments. The latter cover the radiation wavelength range 0...
January 1, 2019: Journal of Synchrotron Radiation
Ethan I L Jull, Helen F Gleeson
An all-optical switchable twisted nematic liquid crystal system has been designed for use as a laser protection filter, which takes advantage of light-induced modification of liquid crystal order. The filter employs photochromic azo-doped liquid crystal mixtures that have been optically characterized and incorporated into a laser filter device. The ability to switch between transmission and blocking modes is shown to occur, even for incredibly low intensity (0.5 mW) irradiation with a continuous 405 nm laser...
December 24, 2018: Optics Express
Vincent Hahn, Sebastian Kalt, Gayathri M Sridharan, Martin Wegener, Shanti Bhattacharya
When light either leaves or enters an optical fiber, one often needs free-space optical components to manipulate the state of polarization or the light's phase profile. It is therefore desirable to integrate such components onto a fiber end facet. In this paper, we realize, for the first time, a polarizing beam splitter fabricated directly onto the end facet of a single-mode optical fiber. The element is composed of a refractive prism, intentionally slightly displaced from the core of the fiber, and an elevated and suspended sub-wavelength diffraction grating, the lamellae of which have an aspect ratio of about 5...
December 10, 2018: Optics Express
Jeongkyun Roh, Jae Hyeon Ryu, Geun Woo Baek, Heeyoung Jung, Seung Gi Seo, Kunsik An, Byeong Guk Jeong, Doh C Lee, Byung Hee Hong, Wan Ki Bae, Jong-Ho Lee, Changhee Lee, Sung Hun Jin
In recent past, for next-generation device opportunities such as sub-10 nm channel field-effect transistors (FETs), tunneling FETs, and high-end display backplanes, tremendous research on multilayered molybdenum disulfide (MoS2 ) among transition metal dichalcogenides has been actively performed. However, nonavailability on a matured threshold voltage control scheme, like a substitutional doping in Si technology, has been plagued for the prosperity of 2D materials in electronics. Herein, an adjustment scheme for threshold voltage of MoS2 FETs by using self-assembled monolayer treatment via octadecyltrichlorosilane is proposed and demonstrated to show MoS2 FETs in an enhancement mode with preservation of electrical parameters such as field-effect mobility, subthreshold swing, and current on-off ratio...
January 13, 2019: Small
Diego Alfonso López-Mora, Albert Flotats, Francisco Fuentes-Ocampo, Valle Camacho, Alejandro Fernández, Agustí Ruiz, Joan Duch, Marina Sizova, Anna Domènech, Montserrat Estorch, Ignasi Carrió
OBJECTIVE: The purpose of this study was to compare image quality and lesion detection capability between a digital and an analog PET/CT system in oncological patients. MATERIALS AND METHODS: One hundred oncological patients (62 men, 38 women; mean age of 65 ± 12 years) were prospectively included from January-June 2018. All patients, who accepted to be scanned by two systems, consecutively underwent a single day, dual imaging protocol (digital and analog PET/CT)...
January 10, 2019: European Journal of Nuclear Medicine and Molecular Imaging
Harisankar S, Kavita Soni, Ekta Yadav, Krushna R Mavani
To understand the effects of oxygen variation in combination of different strain in perovskite nickelates, three sets of PrNiO3-δ thin films (S1, S2 and S3) were deposited on (001) oriented single-crystal wafers of, respectively, SrTiO3, LSAT [(LaAlO3)0.3(Sr2TaAlO 6)0.7] and LaAlO3. Two sets of films, S1 and S2, have tensile strain whereas the films of S3 show compressive strain. For each set, two thin films of fixed thickness (5 nm) were deposited; one film was in-situ annealed in oxygen partial pressure just after deposition and another film was not annealed...
January 10, 2019: Journal of Physics. Condensed Matter: An Institute of Physics Journal
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