Surface emission

2011 ◽  
pp. 225-426 ◽  
Author(s):  
Jean-Pierre Wigneron ◽  
Soren Andersen ◽  
Jacqueline Boutin ◽  
Jean-Christophe Calvet ◽  
Kun-Shan Chen ◽  
...  
Keyword(s):  
Surface Emission

Failure Analysis of Vertical Cavity Surface Emission Laser Diodes

2003 ◽  
Author(s):  
F. Siegelin ◽  
C. Brillert
Keyword(s):  
Failure Analysis ◽  
Complete Analysis ◽  
Cavity Surface ◽  
Dislocation Network ◽  
Plan View ◽  
Surface Emission ◽  
Optical Output ◽  
Vertical Cavity Surface ◽  
Vcsel Arrays ◽  
Vertical Cavity

Abstract A failure analysis case study for oxide confined vertical cavity surface emitting laser (VCSEL) arrays will be presented. The focus of this work is on devices failing with a reduced optical output due to a rapid degradation of the laser diode. The complete analysis flow will be shown, including electrical and optical characterization as well as detailed investigations on a nanometer scale. It is known that these fails are caused by dislocations. An advanced FIB preparation method enabled cross-section and plan view TEM to successfully visualize the complete extent of a dislocation network.

CENTRALITY DEPENDENCE OF NUCLEAR MODIFICATION FACTOR IN Au+Au COLLISIONS AT $\sqrt{s_{NN}}=200~{\rm GeV}$

2007 ◽  
Vol 22 (19) ◽  
pp. 1381-1389 ◽  
Author(s):  
W. C. XIANG ◽  
D. C. ZHOU
Keyword(s):  
Model Calculation ◽  
Centrality Dependence ◽  
Nuclear Modification Factor ◽  
Surface Emission ◽  
Nuclear Modification ◽  
Boltzmann Function ◽  
Modification Factor ◽  
Phenix Data

Centrality dependence of nuclear modification factor at high pT above 4 GeV /c is studied in nucleus–nucleus collisions at [Formula: see text]. We find that the centrality dependence of the nuclear modification factor can be factorized as a Boltzmann function F(b). Comparing our model calculation with PHENIX data, we further confirm that the high pT spectrum of particles is dominated by surface emission.

Spectral and cyclic voltammetric characterization of self-assembled monolayers on gold of pyrene end-labeled oligonucleotide duplexes

1999 ◽  
Vol 77 (5-6) ◽  
pp. 1077-1084 ◽  
Author(s):  
R Scott Reese ◽  
Marye Anne Fox
Keyword(s):  
Gold Surface ◽  
Self Assembled Monolayers ◽  
Self Assembled Monolayer ◽  
Surface Emission ◽  
Assembled Monolayers ◽  
Oligonucleotide Duplex ◽  
Self Assembled ◽  
Duplex Formation

Self-assembled monolayers of sulfur-terminated oligonucleotide duplexes were formed on flat gold surfaces, either by exposure of a self-assembled monolayer bearing one oligonucleotide strand to the complementary strand or by preformation of a oligonucleotide duplex that was then deposited on a fresh gold surface. Virtually identical spectral behavior was observed whether the duplex was produced before deposition or by in situ complementary association. With a duplex bearing an appropriate pyrene end-label, the resulting thin film was photoresponsive. Surface emission measurements show no evidence for pyrene aggregation on the modified surfaces. The polarity of the photocurrent, reflecting photoinduced electron transfer initiated by photoexcitation of pyrene, is opposite that expected from the oligonucleotide-mediated reduction of the appended pyrene excited state.Key words: oligonucleotide, self-assembled monolayer, duplex formation, photoelectrochemistry, surface emission.

Stimulated emission from microcrystalline CsPbBr3 films: Edge emission versus surface emission

2007 ◽  
Vol 137 (1-3) ◽  
pp. 156-161 ◽  
Author(s):  
S. Kondo ◽  
T. Saito ◽  
H. Asada ◽  
H. Nakagawa
Keyword(s):  
Stimulated Emission ◽  
Edge Emission ◽  
Surface Emission

Theoretical study on photoemission of double-layer AlxGa1−xAs/GaAs nanocone array photocathode

2021 ◽  
Author(s):  
Yan Sun ◽  
Lei Liu ◽  
Zhisheng Lv ◽  
Xingyue Zhangyang ◽  
Feifei Lu ◽  
...  
Keyword(s):  
Cross Section ◽  
Light Trapping ◽  
Spectral Response ◽  
Circular Cross Section ◽  
Geometrical Parameters ◽  
Internal Electric Field ◽  
Surface Emission ◽  
The Difference ◽  
Section Structure ◽  
Light Capture

In the design of photocathode, the internal electric field could be formed due to the graded Al compositional [Formula: see text] nanostructure, which can improve the top surface emission probability of carriers. In this paper, [Formula: see text] nanostructure array photocathode composed of two sub-layers is presented. Based on the finite element method, the influence of graded geometrical parameters on their optoelectronic characteristics is investigated. The results show that when the thickness of the sublayer is equal, the difference of the Al composition between the two sublayers of nanostructure is larger, the sub-layers are less, and the quantum efficiency is higher. The light capture ability of the photocathode can be enhanced by increasing the thickness and the array spacing of the first sublayer. Compared with the hexagonal cross-section structure, the light trapping effect and spectral response of the circular cross-section structure are better.

scholarly journals Поверхностно-излучающий квантово-каскадный лазер с кольцевым резонатором

2021 ◽  
Vol 55 (7) ◽  
pp. 602
Author(s):  
А.В. Бабичев ◽  
Е.С. Колодезный ◽  
А.Г. Гладышев ◽  
Д.В. Денисов ◽  
Г.В. Вознюк ◽  
...  
Keyword(s):  
Active Region ◽  
Room Temperature ◽  
Ion Beam ◽  
Whispering Gallery Modes ◽  
Mode Spacing ◽  
Quantum Cascade ◽  
Surface Emission ◽  
Whispering Gallery ◽  
Ring Diameter ◽  
Solid Alloys

The results of studies of quantum-cascade laser with a surface emission through a grating formed in the layers of the top cladding of the waveguide by ion beam milling are presented. The active region of the QCL heterostructure was formed based on a heteropair of In0.53Ga0.47As / Al0.48In0.52As solid alloys with two-phonon resonance design. It is shown that lasing at room temperature close to 7.9 µm is demonstrated for a laser with a ring diameter of 191 µm. The mode spacing corresponds to whispering gallery modes.

scholarly journals Квантово-каскадный лазер с выводом излучения через текстурированный слой

2021 ◽  
Vol 55 (11) ◽  
pp. 1081
Author(s):  
А.В Бабичев ◽  
Е.С Колодезный ◽  
А.Г Гладышев ◽  
Д.В Денисов ◽  
Г.В Вознюк ◽  
...  
Keyword(s):  
Quantum Cascade Laser ◽  
Ion Beam ◽  
Ultrahigh Vacuum ◽  
Far Field ◽  
Field Profile ◽  
Quantum Cascade ◽  
Surface Emission ◽  
Radiation Output

The results of studies of ring quantum-cascade laser with a surface emission with radiation output through a textured layer formed in the layers of the top cladding of the waveguide by ultrahigh vacuum ion beam milling are presented. The far-field profile shows that the radiation is output through the windows with a textured layer in the range of angles of ~ 63–75 degrees to the normal.

scholarly journals Top-down estimation of carbon monoxide emissions from the Mexico Megacity based on FTIR measurements from ground and space

2012 ◽  
Vol 12 (11) ◽  
pp. 29915-29965 ◽  
Author(s):  
W. Stremme ◽  
M. Grutter ◽  
C. Rivera ◽  
A. Bezanilla ◽  
A. R. Garcia ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Spatial Distribution ◽  
Mexico City ◽  
Emission Flux ◽  
Top Down ◽  
Solar Absorption ◽  
Surface Emission ◽  
The Difference ◽  
Anthropogenic Pollutant ◽  
Total Column

Abstract. Continuous carbon monoxide (CO) total column densities above the UNAM campus in Mexico City have been derived from solar absorption infrared spectroscopic measurements since October 2007. Its diurnal evolution is used in the present study in conjunction with other ground-based and satellite data to develop a top-down emission estimate of the annual CO emission of the Mexico City Metropolitan Area (MCMA). The growth-rate of the total column around noon under low ventilation conditions is calculated and allows us to derive the average surface emission-flux at UNAM, while similar measurements taken at the edge of the MCMA in Tecámac provides information on background CO levels in the Mexico basin. Based on 3 yr of measurements, CO column measurements from the IASI satellite instrument are used to reconstruct the spatial distribution of this anthropogenic pollutant over the MCMA. The agreement between the measured columns of the satellite and ground-based measurements is excellent, particularly when a comparison strategy based on time-displaced air masses is used. The annual emission of the Mexico Megacity is estimated to be (2.15 ± 0.5) Tg yr−1 for the year 2008, while the official inventory for that year reported 1.6 Tg yr−1. The difference is slightly higher than the conservative uncertainty estimated in this work suggesting that the emission might be underestimated by the conventional bottom-up method. A larger discrepancy is found in the spatial distribution of the emissions, when comparing the emission flux over UNAM (derived from the ground-based measurement) with that of the inventory integrated over a representative area. The methodology presented here represents a new and useful strategy to evaluate the contribution of megacities to the global anthropogenic gas emissions. Additionally, three different strategies to compare ground and space-based measurements above an inhomogeneous and strongly contaminated area like Mexico City are presented and discussed.

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