Slim: a Personal Computer Based Software for Simulation of Laser Interaction with Materials

1991 ◽  
Vol 236 ◽  
Author(s):  
Rajiv K. Singh ◽  
John Viatella
Keyword(s):  
Laser Irradiation ◽  
Personal Computer ◽  
Rapid Heating ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
Time Dependent ◽  
Intense Laser ◽  
Laser Interaction ◽  
History Of ◽  
Short Laser Pulses

AbstractA user-friendly, personal computer (PC) based routine called SLIM [Simulation of Laser Interaction with Materials] has been developed to understand the non-equilibrium effects of high intensity, short laser pulses on different materials. By employing an accurate implicit finite difference scheme with varying spatial and temporal node dimensions, the time-dependent thermal history of laser-irradiated material can be accurately and quickly determined. This program can take into account the temperature dependent optical and thermal properties of the solid, time dependent laser pulse intensity, and formation and propagation of the melt and/or vaporization interfaces induced by intense laser irradiation. The program can also simulate thermal effects on multilayer structures exposed to pulsed laser irradiation It is expected that this simulation routine will be indispensable to all researchers working in the area of pulsed laser processing of materials, including rapid heating, melting, annealing, laser doping, laser deposition of thin films and laser solidification processing.

Pulsed Laser Mixing of Metal Overlayers on Ceramics

1988 ◽  
Vol 100 ◽  
Author(s):  
R. K. Singh ◽  
N. Biunno ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
Intense Laser ◽  
Interfacial Layers ◽  
Transmission Electron ◽  
Modification Technique ◽  
Mixed Layers ◽  
Metal Overlayers

ABSTRACTPulsed laser mixing has been used as surface modification technique for the improvement in the mechanical properties of ceramics. Thin metallic layers of nickel were deposited on structural silicon nitride and were irradiated with Xenon Chloride (XeCl) laser pulses. The laser parameters were optimized to lead to the formation of mixed layers. The mixed interfacial layers were analyzed using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Rutherford Backscattering (RBS) techniques. Detailed heat flow calculations were performed to simulate the effects of intense laser irradiation on metal coated ceramic structures. The melt lifetimes and the interfacial temperatures obtained using these calculations, were applied to understand the laser mixing phenomena occuring in these layered structures. Thermodynamics of chemical reactions between the metal overlayers and the substrate were done to predict the formation of mixed interfacial layers during laser irradiation.

Time-Resolved X-Ray Studies During Pulsed-Laser Irradiation of Ge

1984 ◽  
Vol 35 ◽  
Author(s):  
J.Z. Tischler ◽  
B.C. Larson ◽  
D.M. Mills
Keyword(s):  
Melting Point ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
High Energy ◽  
Measured Temperature ◽  
Time Resolved ◽  
Synchrotron Source ◽  
X Ray ◽  
Pulsed Laser Irradiation

ABSTRACTSynchrotron x-ray pulses from the Cornell High Energy Synchrotron Source (CHESS) have been used to carry out nanosecond resolution measurements of the temperature distrubutions in Ge during UV pulsed-laser irradiation. KrF (249 nm) laser pulses of 25 ns FWHM with an energy density of 0.6 J/cm2 were used. The temperatures were determined from x-ray Bragg profile measurements of thermal expansion induced strain on <111> oriented Ge. The data indicate the presence of a liquid-solid interface near the melting point, and large (1500-4500°C/pm) temperature gradients in the solid; these Ge results are analagous to previous ones for Si. The measured temperature distributions are compared with those obtained from heat flow calculations, and the overheating and undercooling of the interface relative to the equilibrium melting point are discussed.

Nonlinear time-dependent density functional theory investigation and visualization of ionizations in CO2 — Effects of laser intensities and molecular orientations

2010 ◽  
Vol 88 (11) ◽  
pp. 1186-1194
Author(s):  
Emmanuel Penka Fowe ◽  
André Dieter Bandrauk
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Laser Pulses ◽  
Time Dependent ◽  
Intense Laser ◽  
Functional Theory ◽  
Intense Laser Pulses ◽  
Highest Occupied Molecular Orbital ◽  
Analysis Of The Images ◽  
Dependent Density

Time-dependent density functional theory (TDDFT) studies of the ionization of CO2 by intense laser pulses Io ≥ 1 × 1014 W/cm2, at 800 nm are presented using the LB94 and the LDA potentials. Results reveal that for lower laser peak intensity, Io = 3.5 × 1014 W/cm2, the highest occupied molecular orbital (HOMO) contributes significantly to ionization owing to its lower ionization potential (IP), whereas the inner orbitals play the important role for higher laser peak intensities. Even though such lower orbitals have higher IP, the ionization process occurs when orbital densities are maximum along the direction of the laser field polarization. These findings are confirmed through the analysis of the images from the time-dependent electron localization function (TDELF) and the spectra of higher order harmonic generation (HOHG). Additionally, in spite of the IP difference between Kohn–Sham orbitals from LDA and LB94 potentials, our results show almost the same trend for both.

scholarly journals Numerical stability of time-dependent coupled-cluster methods for many-electron dynamics in intense laser pulses

2020 ◽  
Vol 152 (7) ◽  
pp. 071102 ◽  
Author(s):  
Håkon Emil Kristiansen ◽  
Øyvind Sigmundson Schøyen ◽  
Simen Kvaal ◽  
Thomas Bondo Pedersen
Keyword(s):  
Numerical Stability ◽  
Laser Pulses ◽  
Time Dependent ◽  
Intense Laser ◽  
Coupled Cluster ◽  
Electron Dynamics ◽  
Coupled Cluster Methods ◽  
Intense Laser Pulses ◽  
Cluster Methods

scholarly journals Overcoming Multidrug Resistance by On-Demand Intracellular Release of Doxorubicin and Verapamil

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Jianwei Jiang ◽  
Shaojuan Liu ◽  
Chunlei Wang ◽  
Hongyan Zhang
Keyword(s):  
Multidrug Resistance ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
Chemotherapeutic Agents ◽  
Pulse Number ◽  
Phospholipid Bilayer ◽  
Multidrug Resistance Proteins ◽  
High Concentration ◽  
On Demand

Multidrug resistance (MDR) is one of the major obstacles to the successful application of cancer chemotherapy. Herein, we developed light-responsive doxorubicin-and-verapamil-coencapsulated gold liposomes to overcome MDR. Upon ns-pulsed laser irradiation, the highly confined thermal effect increased the permeability of the phospholipid bilayer, triggering the release of doxorubicin and verapamil, leading to high concentrations in cells. Free verapamil efficiently inhibited the membrane multidrug resistance proteins (MRPs), while the high concentration of doxorubicin saturated MRPs, thus overcoming MDR. We showed that nanosecond- (ns-) pulsed laser- (532 nm, 6 ns) induced doxorubicin release from gold liposomes depended on laser fluence and pulse number. More than 58% of the doxorubicin was released with a 10-pulse irradiation (100 mJ/cm2). Furthermore, ns laser pulses also liberated doxorubicin from endocytosed gold liposomes into the cytosol in MDA-MB-231-R cancer cells. The cytotoxicity of doxorubicin coencapsulated with verapamil was significantly enhanced upon laser irradiation. This study suggested that light-triggered on-demand release of chemotherapeutic agents and MRP inhibitors could be used advantageously to overcome multidrug resistance.

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