Magnetoluminescence Studies in Ordered InGap2

1995 ◽  
Vol 417 ◽  
Author(s):  
E. D. Jones ◽  
R. P. Schneider ◽  
A. Mascarenhas
Keyword(s):  
Magnetic Field ◽  
Power Density ◽  
Laser Power ◽  
Laser Power Density ◽  
Band Spectrum ◽  
Incident Laser ◽  
Electron Hole ◽  
Incident Laser Power ◽  
Power Densities

AbstractPhotoluminescence measurements on ordered InGaP2 were studied as a function of temperature, laser power density, and magnetic field. The temperature varied between 1.4 and 300 K, the laser power densities ranged from 10 nW/cm2 to 20 W/cm2, and the maximum magnetic field was 13.6 T. The data show two spectra, excitonic and band-to-band transitions, depending upon the incident laser power density. A consistent interpretation of the band-to-band spectrum leads to a spatially separated electron-hole transitions between the ordered domains. Three different mechanisms for spatially indirect transitions are presented. An analysis of the linear data also allows a determination of the valence-band mass in the 100 direction of mv ∼0.25 m0.

Research on Pre-Loaded Composite Irradiated by Laser Beam

2011 ◽  
Vol 462-463 ◽  
pp. 872-877 ◽  
Author(s):  
Lian Chun Long ◽  
Zhong Ying Chen ◽  
Zhi Guang Yang
Keyword(s):  
Power Density ◽  
Laser Power ◽  
High Speed ◽  
Laser Power Density ◽  
Failure Behavior ◽  
Time To Failure ◽  
Experiment Data ◽  
Holding Device ◽  
The Relationship ◽  
Power Densities

This paper investigates failure behavior tests of T300/AG80 composite laminated specimens under tensile and compressive preload using a load holding device and laser irradiation from an Nd: YAG laser. By changing the magnitudes of the preload and the power densities of the laser, the effects of preload and laser power density on the time-to-failure of the specimens were observed. The response process of specimens was synchronized taken in using high-speed camera in experiment. The experimental results showed that tensile mechanical properties of T300/AG80 composite laminated specimens were obviously superior to ones in compression test. The relational expressions between the time-to-failure of specimens and pre-loads as well as with laser power densities were acquired through fitting experiment data. The time-to-failure reduced with the pre-load increasing, the relationship is approximating linear when the laser power density kept invariable. When the pre-load kept unchanged, the time-to-failure reduced as the laser power density increased. The relationship is approximating exponential. A basis for life prediction of structure mechanically loaded in either tension or compression during the irradiation by laser is provided by fitting expression.

A tunable positive and negative photoconductive photodetector based on a gold/graphene/p-type silicon heterojunction

2019 ◽  
Vol 7 (4) ◽  
pp. 887-896 ◽  
Author(s):  
Peng-Fei Wang ◽  
Yu Liu ◽  
Jun Yin ◽  
Wanyun Ma ◽  
Zhanmin Dong ◽  
...  
Keyword(s):  
Laser Power ◽  
Incident Laser ◽  
Fast Switching ◽  
Type Silicon ◽  
Incident Laser Power ◽  
P Type ◽  
Power Densities

Fast switching of positive and negative photocurrents of a device under the modulation of different incident laser power densities.

scholarly journals Фотопреобразователь лазерного излучения на основе GaInP с КПД 46.7% на длине волны 600 nm

2022 ◽  
Vol 48 (5) ◽  
pp. 24
Author(s):  
С.А. Минтаиров ◽  
В.В. Евстропов ◽  
М.А. Минтаиров ◽  
М.В. Нахимович ◽  
Р.А. Салий ◽  
...  
Keyword(s):  
Laser Power ◽  
Incident Power ◽  
Incident Laser ◽  
Power Laser ◽  
Chip Design ◽  
Incident Laser Power ◽  
Level Data ◽  
Power Densities ◽  
Iv Curves ◽  
532 Nm

GaInP-based laser power converters (LPC) structure grown by MOVPE and device chip design have been optimized for operation under high-power lasers of the green-red spectral range. Light IV curves records have shown the performance of the LPC up to 40-50 W/cm2 of incident power densities. The highest level data were obtained for 532 nm, 600 nm, and 633 nm power laser lines: 44.3%, 46.7%, and 40.6% under 13-16 W/cm2, respectively. LPC demonstrated an efficiency of more than 40% at elevated up to 40-50 W/cm2 of the incident laser power density.

scholarly journals Neutral and Ionic Particle Emission From a GaAs Surface Induced by the (harmonic) Frequencies of the Nd:YAG Laser

1986 ◽  
Vol 6 (6) ◽  
pp. 349-359 ◽  
Author(s):  
G. R. Möhlmann ◽  
V. A. Kuzmin
Keyword(s):  
Nd:Yag Laser ◽  
Laser Power ◽  
Neutral Particle ◽  
Gaas Surface ◽  
Wave Form ◽  
Incident Laser ◽  
Neutral Particles ◽  
Incident Laser Power ◽  
Power Densities ◽  
Recorded Mass Spectrum

The emission of ionic and neutral particles, resulting from irradiation of a GaAs surface by 1064, 532, 355 and 266 nm Q-switched Nd:YAG laser light, has been studied. Incident laser power densities up to 9.6 × 107 Watts/cm2 have been applied. For 1064, 532 and 355 nm radiations the ratios of ionic to neutral particle emissions are close to the thermal ratio corresponding to the boiling point of Ga. In the case of 266 nm radiation this ratio appears to be higher, which is probably due to non-thermal ion contributions. For several incident wavelengths the emitted yields of ions and neutrals varied with the fifth power of the incident laser power density. The wave form of the emitted ion pulse and the recorded mass spectrum after irradiation at 266 nm differ significantly from those obtained at the other applied wavelengths.

scholarly journals Influence of Saturation Phenomena on Laser-Excited Atomic Fluorescence Flame Spectrometry

1973 ◽  
Vol 28 (2) ◽  
pp. 273-279
Author(s):  
J. Kühl ◽  
S. Neumann ◽  
M. Kriese
Keyword(s):  
Power Density ◽  
Laser Power ◽  
Atomic Emission ◽  
Equation Model ◽  
Laser Power Density ◽  
Atomic Level ◽  
Dye Laser ◽  
Atomic Fluorescence ◽  
Emission Flame ◽  
Flame Spectrometry

Using a simple rate equation model, the laser power density Ic necessary to reach 50% of the saturation limited population of the excited atomic level under typical flame conditions is calculated. For Na atoms aspirated into the flame a saturating power density for irradiation with a narrow dye laser line (bandwidth 0.033 Å) of Ic ~ 0.4 kW/cm2 was determined. With the aid of a dye laser with an appropriate laser power density, analytical curves for Na were measured yielding a detection limit of 0.2 ng/ml. This sensitivity is comparable with the best results obtained by atomic emission flame spectrometry.

Experimental Study on Testing Ni-Containing Stainless Steel Protective Coatings by Pulsed Laser Scratching

2010 ◽  
Vol 43 ◽  
pp. 651-656
Author(s):  
Ai Xin Feng ◽  
Yu Peng Cao ◽  
Chuan Chao Xu ◽  
Huai Yang Sun ◽  
Gui Fen Ni ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Power Density ◽  
Laser Power ◽  
Protective Coatings ◽  
Three Dimensional ◽  
Pulsed Laser ◽  
Laser Power Density ◽  
The Matrix ◽  
The Impact

In the experiment, we use pulsed laser to conduct discrete scratching on Ni-containing stainless steel protective coatings to test residual stress situation after the matrix is scratched; then to analyze the the impact of the impact stress wave on coating - substrate bonding strength according to the test results, finally to infer the laser power density range within which it occurs coating failure. The study shows that: after laser discrete scratching, the residual stress of the center of the laser-loaded point on matrix surface gradually reduces when the pulsed laser power density increases. The matrix produces a corresponding residual compressive stress under the laser power density reaches a certain value. The actual failure threshold values are 12.006 GW/cm2, 11.829GW/cm2 and 12.193GW/cm2 measured by the three-dimensional topography instrument testing the discrete scratch point of three groups of samples and verified by using a microscope

Numerical Simulation and Applications of a Method for Attenuating Laser Power Density

2013 ◽  
Vol 50 (2) ◽  
pp. 022201
Author(s):  
王振宝 Wang Zhenbao ◽  
冯国斌 Feng Guobin ◽  
杨鹏翎 Yang Pengling ◽  
冯刚 Feng Gang ◽  
闫燕 Yan Yan
Keyword(s):  
Numerical Simulation ◽  
Power Density ◽  
Laser Power ◽  
Laser Power Density

scholarly journals Investigation on Residual Stress Loss during Laser Peen Texturing of 316L Stainless Steel

2019 ◽  
Vol 9 (17) ◽  
pp. 3511 ◽  
Author(s):  
Kangmei Li ◽  
Yifei Wang ◽  
Yu Cai ◽  
Jun Hu
Keyword(s):  
Residual Stress ◽  
Compressive Stress ◽  
Power Density ◽  
Laser Power ◽  
Surface Deformation ◽  
Laser Power Density ◽  
Residual Compressive Stress ◽  
Laser Spot ◽  
Residual Tensile Stress ◽  
Spot Radius

Laser peen texturing (LPT) is a novelty way of surface texturing based on laser shock processing. One of the most important benefits of LPT is that it can not only fabricate surface textures but also induce residual compressive stress for the target material. However, the residual stress loss leads to partial loss of residual compressive stress and even causes residual tensile stress at the laser spot center. This phenomenon is not conducive to improving the mechanical properties of materials. In this study, a numerical simulation model of LPT was developed and validated by comparison of surface deformation with experiments. In order to investigate the phenomenon of residual stress loss quantitatively, an evaluation method of residual stress field was proposed. The effects of laser power density and laser spot radius on the residual stress, especially the residual stress loss, were systematically investigated. It is found that with the increase of laser power density or laser spot radius, the thickness of residual compressive layer in depth direction becomes larger. However, both the magnitude and the affecting zone size of residual stress loss will be increased, which implies a more severe residual stress loss phenomenon.

Tuning the Defects in AgO Nanoparticles/Graphene Bilayers System by Laser Power Density

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
H. Ferreira ◽  
M. Briones2, M. Camilo ◽  
G. Poma ◽  
Maria Quintana ◽  
A. Champi
Keyword(s):  
Power Density ◽  
Laser Power ◽  
Laser Power Density
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