APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

3 Nov 2008

Volume 93, Issue 18, Articles (18xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 93, 181101 (2008); http://dx.doi.org/10.1063/1.3009599 (3 pages)

Nanfang Yu, Romain Blanchard, Jonathan Fan, Federico Capasso, Tadataka Edamura, Masamichi Yamanishi, and Hirofumi Kan
Enlarge Image | Read More
Page 1 of 5 Pages Next Page | Jump to Page
back to top
RSS Feeds

Small divergence edge-emitting semiconductor lasers with two-dimensional plasmonic collimators

Nanfang Yu, Romain Blanchard, Jonathan Fan, Federico Capasso, Tadataka Edamura, Masamichi Yamanishi, and Hirofumi Kan

Appl. Phys. Lett. 93, 181101 (2008); http://dx.doi.org/10.1063/1.3009599 (3 pages) | Cited 18 times

Online Publication Date: 3 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using quantum cascade lasers with a two-dimensional metallic aperture-grating structure defined on the facet the authors demonstrate a collimated laser beam with small divergence angle perpendicular and parallel to the laser waveguide layers (2.7° and 3.7°, respectively). These values represent a reduction by a factor of ∼ 30 and ∼ 10, respectively, compared to those of the original 8.06-μm- wavelength laser without plasmonic collimation. The devices preserve good room temperature performance with output power as high as 53% of that of the original unpatterned lasers.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
42.79.Gn Optical waveguides and couplers
42.79.Ag Apertures, collimators
42.82.Cr Fabrication techniques; lithography, pattern transfer

Dynamic surface plasmon patterns generated by reconfigurable “cogwheel-shaped” beams

Z. J. Hu, X.-C. Yuan, S. W. Zhu, G. H. Yuan, P. S. Tan, J. Lin, and Q. Wang

Appl. Phys. Lett. 93, 181102 (2008); http://dx.doi.org/10.1063/1.3005636 (3 pages) | Cited 2 times

Online Publication Date: 3 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A method for generating and controlling dynamic surface plasmon patterns by highly focused “cogwheel-shaped” beams is studied theoretically and experimentally. The “cogwheel” beams are formed by collinear superposition of two Laguerre–Gaussian beams with equal but opposite topological charges. It is shown that the patterned surface plasmons can be reconfigured locally with advantages over patterned metallic islands.
Show PACS
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Silicon photonic crystal nanostructures for refractive index sensing

D. F. Dorfner, T. Hürlimann, T. Zabel, L. H. Frandsen, G. Abstreiter, and J. J. Finley

Appl. Phys. Lett. 93, 181103 (2008); http://dx.doi.org/10.1063/1.3009203 (3 pages) | Cited 21 times

Online Publication Date: 3 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors present the fabrication and optical investigation of silicon on insulator photonic crystal drop filters for use as refractive index sensors. Two types of defect nanocavities (L3 and H1−r) are embedded between two W1 photonic crystal waveguides to evanescently route light at the cavity mode frequency between input and output waveguides. Optical characterization of the structures in air and various liquids demonstrates detectivities in excess of Δn/n = 0.018 and Δn/n = 0.006 for the H1−r and L3 cavities, respectively. The measured cavity frequencies and detector refractive index responsivities are in good agreement with simulations, demonstrating that the method provides a background free transducer signal with frequency selective addressing of a specific area of the sensor chip.
Show PACS
42.82.Et Waveguides, couplers, and arrays
07.60.Hv Refractometers and reflectometers
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
42.70.Qs Photonic bandgap materials
42.79.Ci Filters, zone plates, and polarizers
42.79.Gn Optical waveguides and couplers

Low-loss modes in hollow metallic terahertz waveguides with dielectric coatings

Bradley Bowden, James A. Harrington, and Oleg Mitrofanov

Appl. Phys. Lett. 93, 181104 (2008); http://dx.doi.org/10.1063/1.3013585 (3 pages) | Cited 17 times

Online Publication Date: 3 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Cylindrical hollow-core metallic waveguides with an inner coating of polystyrene (PS) deposited over silver have losses less than 1dB/m for terahertz waves propagating in the HE11 mode. The thickness of the PS film determines whether the hybrid HE11 mode or the transverse TE01 mode exhibits the lowest loss. The mode selection is confirmed by studying mode profiles and transmission losses at 2.5 THz in waveguides with the dielectric coating thickness ranging from 0 to the optimum value of approximately 10 μm.
Show PACS
84.40.Az Waveguides, transmission lines, striplines
07.57.-c Infrared, submillimeter wave, microwave and radiowave instruments and equipment

Chaotic dynamics in semiconductor lasers subjected to polarization-rotated optical feedback

Yasutoshi Takeuchi, Rui Shogenji, and Junji Ohtsubo

Appl. Phys. Lett. 93, 181105 (2008); http://dx.doi.org/10.1063/1.3020302 (3 pages) | Cited 6 times

Online Publication Date: 4 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In-phase or synchronized oscillations between transverse electric (TE) and transverse magnetic (TM) modes with a loop delay are common phenomena in the numerical studies of semiconductor lasers subjected to polarization-rotated optical feedback. However, we experimentally find antiphase oscillations of laser output powers with zero time lag under appropriate conditions of orthogonal polarization optical feedback. Antiphase oscillations are well reproduced by the numerical simulations for the experimental model taking into account the frequency detuning between the two modes.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.65.Sf Dynamics of nonlinear optical systems; optical instabilities, optical chaos and complexity, and optical spatio-temporal dynamics

Electrically pumped ultraviolet ZnO diode lasers on Si

Sheng Chu, Mario Olmedo, Zheng Yang, Jieying Kong, and Jianlin Liu

Appl. Phys. Lett. 93, 181106 (2008); http://dx.doi.org/10.1063/1.3012579 (3 pages) | Cited 68 times

Online Publication Date: 4 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electrically pumped ZnO quantum well diode lasers are reported. Sb-doped p-type ZnO/Ga-doped n-type ZnO with an MgZnO/ZnO/MgZnO quantum well embedded in the junction was grown on Si by molecular beam epitaxy. The diodes emit lasing at room temperature with a very low threshold injection current density of 10 A/cm2. The lasing mechanism is exciton-related recombination and the feedback is provided by close-loop scattering from closely packed nanocolumnar ZnO grains formed on Si.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems

Flexible optical waveguides based on the omnidirectional reflection of one-dimensional photonic crystals

Bing Chen, Tiantong Tang, Zhaohong Wang, Hao Chen, and Zichen Liu

Appl. Phys. Lett. 93, 181107 (2008); http://dx.doi.org/10.1063/1.3020718 (3 pages) | Cited 10 times

Online Publication Date: 5 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An optical wave guiding structure based on the omnidirectional reflection of one-dimensional photonic crystals is presented. The dispersion and transmission characteristics of flexible waveguides using this structure are investigated by numerical simulations using plane wave expansion method and finite-difference time-domain method, respectively. Calculated results indicate that for waveguide bends of arbitrary angles with a curved radius less than several wavelengths, a very high transmission (>97%) over wide frequency range is observed. Owing to this unique advantage of flexibility, it is expected to be applied to highly dense photonic integrated circuits after further research.
Show PACS
42.82.Et Waveguides, couplers, and arrays
02.70.Bf Finite-difference methods
42.70.Qs Photonic bandgap materials
42.79.Gn Optical waveguides and couplers

Experimental observation of narrow surface plasmon resonances in gold nanoparticle arrays

Yizhuo Chu, Ethan Schonbrun, Tian Yang, and Kenneth B. Crozier

Appl. Phys. Lett. 93, 181108 (2008); http://dx.doi.org/10.1063/1.3012365 (3 pages) | Cited 69 times

Online Publication Date: 5 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate that coupling between grating diffraction and localized surface plasmons in two-dimensional gold nanoparticle arrays in water leads to narrow near-infrared resonance peaks in measured far field extinction spectra. Good agreement is obtained between finite difference time domain (FDTD) calculations and experimental extinction spectra. The FDTD calculations predict that the gold nanoparticle arrays exhibit near-field electric field intensity (E2) enhancements approximately one order of magnitude greater than those of single isolated gold nanoparticles.
Show PACS
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
78.68.+m Optical properties of surfaces
42.79.Dj Gratings

Image reconstruction in segmented femtosecond laser-written waveguide arrays

Alexander Szameit, Felix Dreisow, Matthias Heinrich, Thomas Pertsch, Stefan Nolte, Andreas Tünnermann, Eric Suran, Frédéric Louradour, Alain Barthélémy, and Stefano Longhi

Appl. Phys. Lett. 93, 181109 (2008); http://dx.doi.org/10.1063/1.2999624 (3 pages) | Cited 11 times

Online Publication Date: 5 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present the first experimental realization of image reconstruction in finite femtosecond laser-written waveguide arrays with segmentation. The results show that arbitrary field distributions can be imaged in one-dimensional as well as in two-dimensional geometries.
Show PACS
42.79.Gn Optical waveguides and couplers
42.30.Wb Image reconstruction; tomography
42.30.Va Image forming and processing

Energy transfer between silicon–oxygen-related defects and Yb3+ in transparent glass ceramics containing Ba2TiSi2O8 nanocrystals

Song Ye, Bin Zhu, Jin Luo, Yu Teng, Jingxin Chen, G. Lakshminarayana, Guodong Qian, and Jianrong Qiu

Appl. Phys. Lett. 93, 181110 (2008); http://dx.doi.org/10.1063/1.3021086 (3 pages) | Cited 8 times

Online Publication Date: 6 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the conversion of near-ultraviolet radiation of 250–350 nm into near-infrared emission of 970–1100 nm in Yb3+-doped transparent glass ceramics containing Ba2TiSi2O8 nanocrystals due to the energy transfer from the silicon–oxygen-related defects to Yb3+ ions. Efficient Yb3+ emission (2F5/2→2F7/2) was detected under the excitation of defects absorption at 314 nm. The occurrence of energy transfer is proven by both steady state and time-resolved emission spectra, respectively, at 15 K. The Yb2O3 concentration dependent energy transfer efficiency has also been evaluated, and the maximum value is 65% for 8 mol % Yb2O3 doped glass ceramic. These materials are promising for the enhancement of photovoltaic conversion efficiency of silicon solar cells via spectra modification.
Show PACS
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
78.55.Hx Other solid inorganic materials
84.60.Jt Photoelectric conversion
78.47.jd Time resolved luminescence
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
78.20.-e Optical properties of bulk materials and thin films

Theoretical calculations of the carrier induced refractive index change in tensile-strained InGaAsP for use in 1550 nm semiconductor optical amplifiers

Michael J. Connelly

Appl. Phys. Lett. 93, 181111 (2008); http://dx.doi.org/10.1063/1.3021393 (3 pages) | Cited 1 time

Online Publication Date: 6 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nonlinear polarization rotation (NPR) in semiconductor optical amplifiers (SOAs) has applications in all-optical signal processing. Modeling NPR in a SOA requires knowledge of the carrier density induced refractive index change. The tensile-strained bulk SOA has attracted much interest due to its relative ease of fabrication and commercial devices are now available. In this letter we determine the polarization dependent refractive index change in such a SOA, with an InGaAsP active region, operating in the 1550 nm region and investigate its dependence on carrier density and wavelength.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
72.20.Dp General theory, scattering mechanisms
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
42.25.Ja Polarization

Efficient second harmonic generation in ZnO nanorod arrays with broadband ultrashort pulses

Susanta Kumar Das, Martin Bock, Christopher O'Neill, Ruediger Grunwald, Kyung Moon Lee, Hwang Woon Lee, Soonil Lee, and Fabian Rotermund

Appl. Phys. Lett. 93, 181112 (2008); http://dx.doi.org/10.1063/1.3021415 (3 pages) | Cited 10 times

Online Publication Date: 6 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Broadband frequency-doubling properties of c-axis oriented zinc oxide (ZnO) nanorod arrays grown by low-temperature chemical bath method on glass substrate were studied. The maximum effective nonlinearity was found to be about 7.5 times higher than that of a type-I beta-barium borate crystal for a pump intensity of 5.5×1010 W/cm2. The angular dependence of second harmonic generation (SHG) was determined experimentally. The measured spectral profile of SHG was found to be in good agreement with theoretical simulations.
Show PACS
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
61.46.Km Structure of nanowires and nanorods (long, free or loosely attached, quantum wires and quantum rods, but not gate-isolated embedded quantum wires)
81.16.Be Chemical synthesis methods

An improved active region concept for highly efficient GaSb-based optically in-well pumped vertical-external-cavity surface-emitting lasers

Nicola Schulz, Benno Rösener, Rüdiger Moser, Marcel Rattunde, Christian Manz, Klaus Köhler, and Joachim Wagner

Appl. Phys. Lett. 93, 181113 (2008); http://dx.doi.org/10.1063/1.3013311 (3 pages) | Cited 2 times

Online Publication Date: 7 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An improved active region concept for GaSb-based optically pumped vertical-external-cavity surface-emitting lasers (VECSELs) is presented. The concept is based on GaxIn1−xAsySb1−y quantum wells embedded between AlAsySb1−y barrier layers designed for optical in-well pumping. Advantages of this concept are a high modal gain, the suppression of thermal leakage currents, and an improved thermal conductivity of the active region compared to a conventional GaInAsSb/AlGaAsSb active region design. An in-well pumped VECSEL emitting at 2.24 μm has been realized according to this concept, yielding at a heatsink temperature of 20 °C in continuous-wave operation a power slope efficiency of more than 32% and an absorption of the 1.96 μm pump light of more than 50% without pump recycling.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.60.Pk Continuous operation
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Dynamics of photoalignment in azo-dye-doped liquid crystals

Chia-Yi Huang, Yi-Ru Lin, Kuang-Yao Lo, and Chia-Rong Lee

Appl. Phys. Lett. 93, 181114 (2008); http://dx.doi.org/10.1063/1.3021379 (3 pages)

Online Publication Date: 7 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A transmitted light without analyzer was led into the pump-probe twist nematic experiment in azo-dye-doped liquid crystals to observe the light scattering from the dye-adsorbed surface during photoalignment. The morphology of the dye-absorbed surface monitored by this transmitted light is correlated with the formation of the ripple structure, which is reflected by the anchoring of the dye-adsorbed layer, which is, in turn, revealed by measuring the surface director reorientation angle throughout the process. As the regular ripple structure is gradually formed, the Rayleigh scattering is transferred to the Mie scattering since the scale of the ripple structure is at the wavelength.
Show PACS
61.30.Hn Surface phenomena: alignment, anchoring, anchoring transitions, surface-induced layering, surface-induced ordering, wetting, prewetting transitions, and wetting transitions
68.43.-h Chemisorption/physisorption: adsorbates on surfaces
42.70.Df Liquid crystals
78.35.+c Brillouin and Rayleigh scattering; other light scattering

All-optical switching of holographic gratings made of polymer-liquid-crystal-polymer slices containing azo-compounds

Luciano De Sio, Alessandro Veltri, Cesare Umeton, Svetlana Serak, and Nelson Tabiryan

Appl. Phys. Lett. 93, 181115 (2008); http://dx.doi.org/10.1063/1.3021388 (3 pages) | Cited 21 times

Online Publication Date: 7 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present the observation of an all-optical switching effect that takes place when a light beam of suitable wavelength irradiates a “layered” structure made of polymer slices alternated to films of well aligned liquid crystal (LC) which contain also a small percentage of azo-LC molecules. The simple and reliable fabrication procedure exploits a holographic UV curing technique. The observed switching effect takes place in samples that exhibit diffraction efficiency as high as 85% and is induced in less than 0.5 s by an unfocused pump beam of 245 mW/cm2 power density.
Show PACS
42.40.Eq Holographic optical elements; holographic gratings
42.70.Jk Polymers and organics
42.70.Df Liquid crystals
back to top
RSS Feeds

Living tissue under treatment of cold plasma atmospheric jet

A. Shashurin, M. Keidar, S. Bronnikov, R. A. Jurjus, and M. A. Stepp

Appl. Phys. Lett. 93, 181501 (2008); http://dx.doi.org/10.1063/1.3020223 (3 pages) | Cited 63 times

Online Publication Date: 4 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The interaction of the cold atmospheric plasma jet with fibroblast cells was studied. Plasma jet was initiated in the helium flow blowing through the syringe by application of high ac voltage to the discharge electrodes. The plasma jet had a length of 5 cm and a diameter of 1.5–2 mm in ambient air. Treatment of cells with plasma jet resulted in decreasing of cell migration rate, cell detachment, and appearance of “frozen” cells, while treatment with helium flow (no plasma) resulted in appearance of frozen cells only. A variety of cellular responses was explained by different intensities of treatment.
Show PACS
87.85.-d Biomedical engineering
52.75.-d Plasma devices
52.77.Fv High-pressure, high-current plasmas (plasma spray, arc welding, etc.)
87.17.Jj Cell locomotion, chemotaxis
back to top
RSS Feeds

Interfacial structure and chemistry of epitaxial CoFe2O4 thin films on SrTiO3 and MgO substrates

S. Xie, J. Cheng, B. W. Wessels, and V. P. Dravid

Appl. Phys. Lett. 93, 181901 (2008); http://dx.doi.org/10.1063/1.3006060 (3 pages) | Cited 10 times

Online Publication Date: 3 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Interfacial structure and chemistry of epitaxial CoFe2O4 thin films on (001)_SrTiO3 and (001)_MgO substrates were investigated using high-angle-annular-dark-field imaging combined with electron-energy-loss-spectra (EELSs) analyses at a subnanometer scale. The results show that CoFe2O4/SrTiO3 interface is semicoherent with requisite dislocation density to accommodate ∼ 7% lattice mismatch, while the small ( ∼ 0.3%) lattice mismatch renders CoFe2O4/MgO interface coherent. EELS indicates that Fe valence is nominally +3, with no measurable change across the interfaces. Structural characterization corroborates with observed lower saturation magnetization of CoFe2O4 on MgO, which is a consequence of tensile stress built up in the 〈100〉-direction negative magnetostrictive CoFe2O4.
Show PACS
68.35.Ct Interface structure and roughness
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
75.50.Dd Nonmetallic ferromagnetic materials
75.70.Ak Magnetic properties of monolayers and thin films
79.20.Uv Electron energy loss spectroscopy
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)

Molecular beam epitaxy growth of wurtzite AlN nanotips

Kuang-Yuan Hsu, Chuan-Pu Liu, Hung-Chin Chung, and Yu-Chen Chiu

Appl. Phys. Lett. 93, 181902 (2008); http://dx.doi.org/10.1063/1.3013573 (3 pages)

Online Publication Date: 3 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The characteristics of structure and morphology of AlN nanotips grown under higher V/III ratio on Si (111) with plasma-assisted molecular beam epitaxy are herein investigated. We found that the AlN nanotips were single crystalline with {1-211} inclined facets and embedded in pitlike defects of N-polarity. The density and size of the AlN nanotips can be controlled by the growth conditions. The AlN nanotip growth mechanism can be rationalized as the c-type dislocations generated between two adjacent grains due to the formation of higher strain area in the early stages of growth. The c-type dislocation would reverse the stacking sequence of the following adatoms, leading to the AlN nanotip growth with inverse polarity and higher growth rate compared to the surrounding matrix. These nanotips might serve as the ideal templates for further growth of nanostructure devices.
Show PACS
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
71.55.Eq III-V semiconductors
52.77.-j Plasma applications
68.55.ag Semiconductors
81.16.-c Methods of micro- and nanofabrication and processing
68.35.B- Structure of clean surfaces (and surface reconstruction)

High fidelity optical readout of excited-state lifetimes and ionization of hydrogenic donors in GaAs

D. G. Allen, Sangwoo Kim, C. R. Stanley, and M. S. Sherwin

Appl. Phys. Lett. 93, 181903 (2008); http://dx.doi.org/10.1063/1.3020222 (3 pages)

Online Publication Date: 4 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Optical detection of terahertz-frequency Rydberg transitions of neutral donors in GaAs is demonstrated via state-dependent resonance fluorescence from the neutral donor bound exciton (D0X) transition. The intensity of the elastically scattered light is proportional to the fraction of donor-bound electrons in the (bright) ground state; excited state and ionized donors are dark. Resonance fluorescence recovery after terahertz excitation yields a single-shot, time-resolved measurement of the lifetime of the lowest excited (2P−) state. We also demonstrate contactless detection of electron ionization/capture via the ionized donor exciton (D+X) transition.
Show PACS
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
71.35.-y Excitons and related phenomena
72.80.Ey III-V and II-VI semiconductors

Core/shell structures of oxygen-rich nanofeatures in oxide-dispersion strengthened Fe–Cr alloys

Emmanuelle A. Marquis

Appl. Phys. Lett. 93, 181904 (2008); http://dx.doi.org/10.1063/1.3000965 (3 pages) | Cited 31 times

Online Publication Date: 4 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
With the significant improvement in high temperature creep properties and resistance to radiation damage by addition of nanoscale oxide features, oxide-dispersion strengthened (ODS) ferritic/martensitic alloys are potential candidates for structural applications in nuclear fusion reactors. The structure of the oxygen-rich nanofeatures was analyzed by atom-probe tomography in three ODS alloys: MA957, ODS Fe–12 wt %Cr, and ODS Eurofer-97. Although field evaporation and reconstruction of the precipitates suffer from artefacts, a core/shell structure is found even for very small precipitates. Precipitate cores are Y rich while shell regions are enriched in Ti, Cr, or V depending on alloy composition.
Show PACS
62.20.Hg Creep
81.40.Lm Deformation, plasticity, and creep
61.80.-x Physical radiation effects, radiation damage

Laser generation and detection of longitudinal and shear acoustic waves in a diamond anvil cell

Nikolay Chigarev, Pavel Zinin, Li-Chung Ming, George Amulele, Alain Bulou, and Vitalyi Gusev

Appl. Phys. Lett. 93, 181905 (2008); http://dx.doi.org/10.1063/1.3013587 (3 pages) | Cited 9 times

Online Publication Date: 4 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Laser ultrasonics in a point-source-point-receiver configuration is applied for the evaluation of elastic properties of nontransparent materials in a diamond anvil cell at high pressures. Measurement of both longitudinal and shear acoustic wave velocities in an iron foil at pressures up to 23 GPa does not require any information in addition to the one obtained by all-optical pump-probe technique.
Show PACS
62.65.+k Acoustical properties of solids
81.40.Jj Elasticity and anelasticity, stress-strain relations
62.20.D- Elasticity
62.50.-p High-pressure effects in solids and liquids
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
81.70.Cv Nondestructive testing: ultrasonic testing, photoacoustic testing

Origin of highly spatially selective etching in deeply implanted complex oxides

Avishai Ofan, Ophir Gaathon, Lakshmanan Vanamurthy, Sasha Bakhru, Hassaram Bakhru, Kenneth Evans-Lutterodt, and Richard M. Osgood, Jr.

Appl. Phys. Lett. 93, 181906 (2008); http://dx.doi.org/10.1063/1.3013821 (3 pages) | Cited 1 time

Online Publication Date: 4 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The origin of the rate of anomalously high spatially selective etching of a buried heavily implanted region in complex oxides is studied. Single-crystal LiNbO3 samples are prepared with a 0.4 μm wide implanted region at depth of 10 μm, using 5×1016 cm−2 fluence of 3.8 MeV He+, and wet etched after a low-temperature anneal. An etch-rate enhancement of 104 is found after implantation and low-temperature 175–275 °C post-implantation annealing. Experiments using time-resolved optical microscopy, x-ray diffraction, and proximal-probe microscopy show that this enhancement arises from the more rapid etch-solution transport in the microdomain network formed in the implanted region after annealing.
Show PACS
61.72.up Other materials
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization
61.72.Cc Kinetics of defect formation and annealing
81.65.Cf Surface cleaning, etching, patterning

Direct observations of Ca ordering in Ca0.33CoO2 thin films with different superstructures

Rong Huang, Teruyasu Mizoguchi, Kenji Sugiura, Hiromichi Ohta, Kunihito Koumoto, Tsukasa Hirayama, and Yuichi Ikuhara

Appl. Phys. Lett. 93, 181907 (2008); http://dx.doi.org/10.1063/1.3021369 (3 pages) | Cited 5 times

Online Publication Date: 5 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Ca-ion superstructures such as matha×matha (hexagonal) and 2a×matha (orthorhombic) in layered Ca0.33CoO2 crystalline film, which were prepared by the reactive solid-phase epitaxy and the subsequent ion-exchange treatment, were directly distinguished by using spherical-aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The fluctuation of Ca intensities in the HAADF-STEM image indicates the existence of many Ca vacancies in the 2a×matha orthorhombic superstructure, which is consistent with the partial occupation of Ca (x = 0.33) in the cation sites of x = 0.5.
Show PACS
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
61.72.jd Vacancies
81.15.Np Solid phase epitaxy; growth from solid phases

Atomic layer structure of manganese atoms on wurtzite gallium nitride (000math)

Abhijit Chinchore, Kangkang Wang, Wenzhi Lin, Jeongihm Pak, and Arthur R. Smith

Appl. Phys. Lett. 93, 181908 (2008); http://dx.doi.org/10.1063/1.3006434 (3 pages) | Cited 1 time

Online Publication Date: 5 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Submonolayer quantities of Mn are deposited on wurtzite GaN (000math). The surface is monitored using reflection high energy electron diffraction, which shows a pattern consisting of 3× reconstruction along [10math0], but only 1× along [11math0]. Diffraction analysis shows that the 3× streak intensity is maximized at ≈ 0.86 monolayer of Mn deposition. The results indicate that Mn forms linear chains along the [10math0] direction with a spacing of matha/2 along chains and 3a/2 between chains. Correcting the peak coverage for sticking coefficient and accounting for the observed periodicities, a math×math-R30° model, consisting of 2/3 monolayer of Mn atoms, is proposed.
Show PACS
68.55.-a Thin film structure and morphology
68.35.bd Metals and alloys
68.47.Fg Semiconductor surfaces

Electro-optically tuned defect mode in structurally chiral materials

Laura O. Palomares and Juan Adrian Reyes

Appl. Phys. Lett. 93, 181909 (2008); http://dx.doi.org/10.1063/1.3020715 (3 pages) | Cited 1 time

Online Publication Date: 6 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We considered an orthorhombic mm2 structurally chiral material, susceptible to the Pockels effect having a twist defect and subjected to a dc electric field oriented along the nonhomogeneity axis. We found that its localized mode can be tuned and the scaling of the inverse relative linewidth can be largely enhanced when the magnitudes of the field and the tilt angle of the structure are near the pseudoisotropic curve. This tuning gives rise to a dramatic variation in the behavior of the photon dwell time for the defect mode, which never reaches a maximum by increasing the sample thickness.
Show PACS
78.20.Jq Electro-optical effects
78.20.Ek Optical activity
Page 1 of 5 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close