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

1 Aug 2011

Volume 99, Issue 5, Articles (05xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 99, 051112 (2011); http://dx.doi.org/10.1063/1.3617421 (3 pages)

Wei Li, Jun Chen, Gerard Nouet, Liang-yao Chen, and Xunya Jiang
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

O-band excited state quantum dot bilayer lasers

M. A. Majid, D.T.D. Childs, K. Kennedy, R. Airey, R. A. Hogg, E. Clarke, P. Spencer, and R. Murray

Appl. Phys. Lett. 99, 051101 (2011); http://dx.doi.org/10.1063/1.3605590 (3 pages) | Cited 1 time

Online Publication Date: 1 August 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Bilayer InAs/GaAs quantum dot (QD) lasers operating in the excited state at wavelengths that span the O-band are demonstrated. The higher saturated gain and lower scattering time of the excited states of the ensemble of QDs offers the opportunity for fast direct-modulation lasers. We predict an increase in K-factor limited modulation bandwidth from QD lasers operating in the excited state due to a reduction in carrier transport and scattering times whilst maintaining high peak modal gain.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
68.47.Fg Semiconductor surfaces
42.60.Fc Modulation, tuning, and mode locking

Room temperature spin relaxation length in spin light-emitting diodes

Henning Soldat, Mingyuan Li, Nils C. Gerhardt, Martin R. Hofmann, Arne Ludwig, Astrid Ebbing, Dirk Reuter, Andreas D. Wieck, Frank Stromberg, Werner Keune, and Heiko Wende

Appl. Phys. Lett. 99, 051102 (2011); http://dx.doi.org/10.1063/1.3622662 (3 pages) | Cited 8 times

Online Publication Date: 2 August 2011

Full Text: Read Online (HTML) | Download PDF


See Also: Erratum

Show Abstract
We investigate the spin relaxation length in GaAs spin light-emitting diode devices under drift transport at room temperature. The spin-polarised electrons are injected through a MgO tunnel barrier from a Fe/Tb multilayer in magnetic remanence. The decrease in circular polarization with increasing injection path length is investigated and found to be exponential, supporting drift-based transport. The spin relaxation length in our samples is 26 nm, and a lower bound for the spin injection efficiency at the spin injector/GaAs interface is estimated to be 25 ± 2%.
Show PACS
85.60.Jb Light-emitting devices
75.76.+j Spin transport effects
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
72.25.-b Spin polarized transport

On the optical polarization properties of semipolar InGaN quantum wells

L. Schade, U. T. Schwarz, T. Wernicke, J. Rass, S. Ploch, M. Weyers, and M. Kneissl

Appl. Phys. Lett. 99, 051103 (2011); http://dx.doi.org/10.1063/1.3618676 (3 pages) | Cited 7 times

Online Publication Date: 2 August 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Polarized photoluminescence of strained quantum wells grown on c–plane, semipolar (10math2), (11math2), (10math1), (20math1) planes, and nonpolar GaN substrates was studied experimentally and in theory. The observed optical polarization switching between the substrate orientations (10math2) and (11math2) is in accordance with our general model of polarization switching, based on a math·math model of arbitrary substrate orientation. Spectrally resolved measurements of the polarization degree stemming from (10math2) samples show that the maximum of the polarization degree is red–shifted with respect to the maximum of the photoluminescence intensity. We ascribe this effect to an increased polarization of the transitions for higher indium content.
Show PACS
78.66.Fd III-V semiconductors
78.67.De Quantum wells
78.55.Cr III-V semiconductors

1 × 12 Unequally spaced waveguide array for actively tuned optical phased array on a silicon nanomembrane

David Kwong, Amir Hosseini, Yang Zhang, and Ray T. Chen

Appl. Phys. Lett. 99, 051104 (2011); http://dx.doi.org/10.1063/1.3619847 (3 pages) | Cited 5 times

Online Publication Date: 2 August 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present an experimental demonstration of an optical phased array implementation on silicon nanomembrane. The integrated on-chip array configuration is non-uniform and avoids grating lobes inside the field of view during beam steering while allowing the waveguide separation to be large enough to prevent optical coupling. A 1 × 12 multimode interference beam splitter uniformly excites the arrayed waveguides. Individually controllable micro-heaters modulate the optical phase in the arrayed waveguides. A beam steering angle of 10.2° in a silicon planar guide equivalent to an effective steering angle of 31.9° in air is demonstrated at 1.55 μm.
Show PACS
42.79.Gn Optical waveguides and couplers
42.82.-m Integrated optics

A microfiber cavity with minimal-volume confinement

Ming Ding, Pengfei Wang, Timothy Lee, and Gilberto Brambilla

Appl. Phys. Lett. 99, 051105 (2011); http://dx.doi.org/10.1063/1.3621836 (3 pages) | Cited 6 times

Online Publication Date: 2 August 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate a type of microcavity with minimal-volume confinement using a high-contrast phase-shifted Bragg grating in a microfiber. While waveguiding by the air-silica boundary provides a diffraction-limited two-dimensional confinement, the grating introduces the third degree of confinement. Theoretical simulations verified the microfiber cavity confinement while the experimental demonstration, carried out in samples nanostructured by focused ion beam, showed a good agreement with theoretical predictions. This cavity can be used for a variety of applications ranging from sensing to quantum dynamic experiments.
Show PACS
42.81.Wg Other fiber-optical devices
42.65.-k Nonlinear optics
42.79.Dj Gratings

Backward growth of plasma induced by long nanosecond laser pulse ablation

Yun Zhou, Sha Tao, and Benxin Wu

Appl. Phys. Lett. 99, 051106 (2011); http://dx.doi.org/10.1063/1.3621855 (3 pages) | Cited 3 times

Online Publication Date: 2 August 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An interesting physical phenomenon of laser-induced plasma backward growth has been found for long nanosecond (ns) laser pulse ablation, which has been rarely reported. Time-resolved observation shows that the plasma bottom appears to be detached from the ablated target surface shortly after laser pulse ends, and then the bottom grows backwards towards the target. This phenomenon is understood through an experimentally verified, physics-based model. The study shows that the plasma backward growth is fundamentally the backward growth of high-temperature region bottom boundary without any significant backward motion of material, and the underlying gas dynamic process has also been revealed.
Show PACS
52.50.Jm Plasma production and heating by laser beams (laser-foil, laser-cluster, etc.)
52.70.Kz Optical (ultraviolet, visible, infrared) measurements
52.38.Mf Laser ablation

Ultralow power all-optical diode in photonic crystal heterostructures with broken spatial inversion symmetry

Cuicui Lu, Xiaoyong Hu, Yingbo Zhang, Zhiqiang Li, Xin’an Xu, Hong Yang, and Qihuang Gong

Appl. Phys. Lett. 99, 051107 (2011); http://dx.doi.org/10.1063/1.3617433 (3 pages) | Cited 7 times

Online Publication Date: 3 August 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We experimentally realize an all-optical diode in a photonic crystal heterostructure with broken spatial inversion symmetry. The physical mechanism is attributed to bandgaps only for certain wavevectors and the transition between different electromagnetic Bloch modes, without any nonlinearity and high power requirement. An ultralow photon intensity of 50 kW/cm2 and an ultrahigh transmission contrast of over 103 are reached simultaneously. Compared with previous reported all-optical diodes, the operating power is reduced by seven orders of magnitude, while the transmission contrast is enlarged by two orders of magnitude. This approach may open a way for the study of integrated photonic devices.
Show PACS
42.70.Qs Photonic bandgap materials
85.60.Dw Photodiodes; phototransistors; photoresistors

Subwavelength lateral confinement of microwave surface waves

Elizabeth M. G. Brock, Euan Hendry, and Alastair P. Hibbins

Appl. Phys. Lett. 99, 051108 (2011); http://dx.doi.org/10.1063/1.3622646 (3 pages) | Cited 6 times

Online Publication Date: 3 August 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Experimental verification of the “domino plasmon,” recently proposed by Cano et al. [Opt. Express 18(2), 754, (2010)] is presented. Using microwaves, it is demonstrated that this mode propagates along a periodic chain of metallic cuboids (“dominos”) and the dispersion of the mode is determined with results being compared to the predictions of analytical and numerical models. This mode is found to be surprisingly insensitive to the lateral width of the chain, even on a subwavelength scale. Having such tight confinement, “domino plasmons” show considerable promise for one-dimensional subwavelength guiding and focusing of electromagnetic fields.
Show PACS
84.40.Az Waveguides, transmission lines, striplines
41.20.Jb Electromagnetic wave propagation; radiowave propagation
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)

High optical polarization ratio from semipolar (20mathmath) blue-green InGaN/GaN light-emitting diodes

Yuji Zhao, Shinichi Tanaka, Qimin Yan, Chia-Yen Huang, Roy B. Chung, Chih-Chien Pan, Kenji Fujito, Daniel Feezell, Chris G. Van de Walle, James S. Speck, Steven P. DenBaars, and Shuji Nakamura

Appl. Phys. Lett. 99, 051109 (2011); http://dx.doi.org/10.1063/1.3619826 (3 pages) | Cited 6 times

Online Publication Date: 3 August 2011

Full Text: Read Online (HTML) | Download PDF


See Also: Publisher's Note

Show Abstract
The optical polarization ratio of spontaneous emission was investigated by electroluminescence measurements for semipolar (20mathmath) InGaN/GaN light-emitting diodes, covering the blue to green spectral range. Devices fabricated on semipolar (20mathmath) substrates exhibit polarization ratios ranging from 0.46 at 418 nm to 0.67 at 519 nm. These polarization ratios are significantly higher than those reported on semipolar (20math1) devices. The valence band energy separation is extracted from spectral measurements and is consistent with the increased polarization ratio and theoretical predictions. Quantum well interdiffusion induced valence band mixing is suggested as a possible explanation for the low experimental value of polarization ratio observed for the (20math1) devices.
Show PACS
85.60.Jb Light-emitting devices

Strong coupling between surface plasmon polariton and laser dye rhodamine 800

Federico Valmorra, Markus Bröll, Stephan Schwaiger, Nadine Welzel, Detlef Heitmann, and Stefan Mendach

Appl. Phys. Lett. 99, 051110 (2011); http://dx.doi.org/10.1063/1.3619845 (3 pages) | Cited 1 time

Online Publication Date: 3 August 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on strong coupling between surface plasmon polaritons on a thin silver film and laser dye Rhodamine 800. Attenuated total reflection measurements reveal that the pure surface plasmon polaritons interact with the Rhodamine 800 absorption lines exhibiting pronounced anticrossings in the dispersion relation. We show that the corresponding energy gap can be tailored by the concentration of dye molecules in the dielectric matrix between 50 meV and 70 meV. We can well model our data by a classical transfer matrix approach as well as by a quantum mechanical coupled oscillator ansatz.
Show PACS
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
78.40.Kc Metals, semimetals, and alloys
78.66.Bz Metals and metallic alloys
71.36.+c Polaritons (including photon-phonon and photon-magnon interactions)

Angular emission properties of a layer of rare-earth based nanophosphors embedded in one-dimensional photonic crystal coatings

O. Sánchez-Sobrado, A. M. Yacomotti, M. E. Calvo, O. E. Martínez, M. Ocaña, N. Núñez, J. A. Levenson, and H. Míguez

Appl. Phys. Lett. 99, 051111 (2011); http://dx.doi.org/10.1063/1.3619814 (3 pages) | Cited 1 time

Online Publication Date: 4 August 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The angular properties of light emitted from rare-earth based nanophosphors embedded in optical resonators built in one-dimensional photonic crystal coatings are herein investigated. Strong directional dependence of the photoluminescence spectra is found. Abrupt angular variations of the enhancement caused by the photonic structure and the extraction power are observed, in good agreement with calculated polar emission patterns. Our results confirm that the optical cavity favors the extraction of different wavelengths at different angles and that integration of nanophosphors within photonic crystals provides control over the directional emission properties that could be put into practice in phosphorescent displays.
Show PACS
42.70.Qs Photonic bandgap materials
42.79.Wc Optical coatings
78.55.Hx Other solid inorganic materials
42.55.Tv Photonic crystal lasers and coherent effects

The methods to detect vacuum polarization by evanescent modes

Wei Li, Jun Chen, Gerard Nouet, Liang-yao Chen, and Xunya Jiang

Appl. Phys. Lett. 99, 051112 (2011); http://dx.doi.org/10.1063/1.3617421 (3 pages) | Cited 2 times

Online Publication Date: 4 August 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose the evanescent-mode-sensing methods to probe the quantum electrodynamics (QED) vacuum polarization. From our methods, high-sensitivity can be achieved even though the external field is much smaller than the Schwinger critical field and may be realizable in contemporary experimental conditions. The methods are based on the effect of phase change and time delay of evanescent wave which is transmitted in QED vacuum.
Show PACS
42.81.Pa Sensors, gyros

Solid-state optimal phase-covariant quantum cloning machine

Xin-Yu Pan, Gang-Qin Liu, Li-Li Yang, and Heng Fan

Appl. Phys. Lett. 99, 051113 (2011); http://dx.doi.org/10.1063/1.3624595 (3 pages) | Cited 5 times

Online Publication Date: 5 August 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Here, we report an experimental realization of optimal phase-covariant quantum cloning machine with a single electron spin in solid state system at room temperature. The involved three states of two logic qubits are encoded physically in three levels of a single electron spin with two Zeeman sub-levels at a nitrogen-vacancy defect center in diamond. The preparation of input state and the phase-covariant quantum cloning transformation is controlled by two independent microwave fields. The average experimental fidelity reaches 85.2% which is very close to theoretical optimal fidelity 85.4% and is beyond the bound 83.3% of universal cloning.
Show PACS
03.67.Ac Quantum algorithms, protocols, and simulations
03.67.Lx Quantum computation architectures and implementations
61.72.jd Vacancies
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close