Shadowgraphic Imaging of Dilute Carbon and Mo2Ag4S8,[PPh3]4 Suspensions

1997 ◽  
Vol 479 ◽  
Author(s):  
Robert Goedert ◽  
Roger Becker ◽  
Andrew Clements ◽  
Thomas Whittaker
Keyword(s):  
Carbon Particle ◽  
Input Pulse ◽  
Laser Pulses ◽  
Focal Volume ◽  
Time Resolved ◽  
Nonlinear Materials ◽  
Input Pulse Energy ◽  
Laser Induced Breakdown ◽  
Plasma Absorption ◽  
Keywords Laser

AbstractTime-resolved imagery is presented showing the changes that occur in the focal volume of dilute liquid/particle suspensions following the arrival of single, Q-switched, frequency-doubled, Nd:YAG laser pulses. Limiting data and corresponding imagery at 21, 84, 244, 790, and 2900 nanoseconds following the laser pulse are presented for a carbon particle suspension consisting of used (carbonized) 1OW-15 motor oil and for a suspension of the inorganic metallic cluster molecule Mo2Ag4S8 [PPh3]4. The images in conjunction with the accompanying limiting data show that the reduction in transmission, observed as the input pulse energy is increased, results from scattering from bubbles augmented by plasma absorption. Keywords: laser induced breakdown, plasma, suspension, bubble, nonlinear materials, shadowgraph, imagery

Laser Ablation-Induced Plasma Characteristics in Optical Near-Field

2007 ◽  
Author(s):  
David J. Hwang ◽  
Hojeong Jeon ◽  
Costas P. Grigoropoulos
Keyword(s):  
Near Infrared ◽  
Near Field ◽  
Laser Pulses ◽  
Thin Metal Film ◽  
Nanosecond Laser ◽  
Time Resolved ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Nanosecond Laser Pulses ◽  
Plasma Characteristics

In this study, detailed characteristics of the optical near-field based ablation-induced plasma are investigated. A Cr thin metal film samples are ablated using visible and near infrared nanosecond laser pulses coupled through an optical near-field fiber probe. The ablated plasma evolution is visualized through time-resolved emission imaging and further analyzed via spectral measurement. Unveiled qualitative differences in optical near-field ablation configuration are discussed in comparison with optical far-field ablation. The measured results support implementation of laser-induced breakdown spectroscopy based on optical near-field ablation.

scholarly journals Development of time-resolved laser-induced fluorescence spectroscopic technique for the analysis of biomolecules

2008 ◽  
Vol 6 (1) ◽  
pp. 105-117 ◽  
Author(s):  
M. Terzic ◽  
B.P. Marinkovic ◽  
D. Sevic ◽  
J. Jureta ◽  
A.R. Milosavljevic
Keyword(s):  
Detection System ◽  
Laser Pulses ◽  
Laser Induced Fluorescence ◽  
Spectroscopic Technique ◽  
Pressure Effects ◽  
Time Resolved ◽  
Pulse Delay ◽  
Digital Pulse ◽  
Laser Induced Breakdown ◽  
Temperature And Pressure Effects

Our developments of the time-resolved laser-induced fluorescence (TR-LIF) detection system for biomolecules are presented. This system is based on the tunable (320 nm to 475 nm) Nd:YAG laser pulses used to excite various biomolecules. The detection part is the Streak System for Fluorescence Lifetime Spectroscopy (Hamamatsu, Japan). The system consists of a C4334-01 streakscope, as a detector, DG 535 digital pulse/delay generator, C5094-S Spectrograph and HPD-TA System, as a temporal analyzer. The TR-LIF spectrometer is designed primarily to study the temperature and pressure effects on fluorescence behavior of biomolecules upon excitation with a single nanosecond pulse. The design of this system has capability to combine laser-induced breakdown (LIB) with fluorescence, as well to study optodynamic behavior of fluorescence biomolecules.

scholarly journals Circularly-polarized THz wave emission from a micro-thin water flow

2021 ◽  
Author(s):  
Hsin-hui Huang ◽  
Saulius Juodkazis ◽  
Eugene Gamaly ◽  
Takeshi Nagashima ◽  
Tetsu Yonezawa ◽  
...  
Keyword(s):  
Water Flow ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Intense Laser ◽  
Practical Implementation ◽  
Focal Volume ◽  
Time Resolved ◽  
Circularly Polarized ◽  
Thz Wave ◽  
Wave Emission

Abstract Intense THz wave sources are highly expected for further progresses in nonlinear THz science and practical implementation of non-ionizing radiation in sensing and communications. Solid-based sources have inherent limits of material breakdown, while intense laser irradiation of liquids is a promising emerging technique for THz wave and hard X-ray emission. Water-based THz emission shows intensity enhancements up to 10 times when laser-pulse pairs with nanosecond delay are used. Here we show circularly-polarized THz wave emission from thin water flow irradiated by two time-separated and linearly-polarized femtosecond laser pulses. THz time-domain spectroscopy reveals the circularly-polarized THz emission dominates 4.7 ns after the first pulse irradiation. THz wave detection delay in the spectroscopy and time-resolved micrography indicate that the THz wave emission originates from the rarefied volume in front of the flow. Radial relaxation of charges in the focal volume where ponderomotive charge depletion occurred on the optical axis is the origin for the circular polarization (due to spiraling currents). Tight focusing of fs-laser pulses localized THz wave emission to the sub-wavelength (tens-of-micrometers) region.

Time-resolved study of the plasma produced from animal muscle tissue using a Nd:YAG laser

2018 ◽  
Vol 33 (11) ◽  
pp. 1884-1891 ◽  
Author(s):  
S. Moncayo ◽  
A. Marín-Roldán ◽  
S. Manzoor ◽  
J. J. Camacho ◽  
V. Motto-Ros ◽  
...  
Keyword(s):  
Muscle Tissue ◽  
Nd:Yag Laser ◽  
Laser Pulses ◽  
Laser Induced Breakdown Spectroscopy ◽  
Time Resolved ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Animal Muscle

This paper reports studies on time-resolved laser induced breakdown spectroscopy (LIBS) of plasmas induced by Nd:YAG laser pulses on a sample lyophilized from swine muscle tissue.

scholarly journals Dual-shot dynamics and ultimate frequency of all-optical magnetic recording on GdFeCo

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Sicong Wang ◽  
Chen Wei ◽  
Yuanhua Feng ◽  
Hongkun Cao ◽  
Wenzhe Li ◽  
...  
Keyword(s):  
Magnetization Reversal ◽  
Energy Efficient ◽  
High Speed ◽  
Data Transfer ◽  
Laser Pulses ◽  
Time Resolved ◽  
All Optical ◽  
Fs Laser ◽  
High Speed Data ◽  
Natural Way

AbstractAlthough photonics presents the fastest and most energy-efficient method of data transfer, magnetism still offers the cheapest and most natural way to store data. The ultrafast and energy-efficient optical control of magnetism is presently a missing technological link that prevents us from reaching the next evolution in information processing. The discovery of all-optical magnetization reversal in GdFeCo with the help of 100 fs laser pulses has further aroused intense interest in this compelling problem. Although the applicability of this approach to high-speed data processing depends vitally on the maximum repetition rate of the switching, the latter remains virtually unknown. Here we experimentally unveil the ultimate frequency of repetitive all-optical magnetization reversal through time-resolved studies of the dual-shot magnetization dynamics in Gd27Fe63.87Co9.13. Varying the intensities of the shots and the shot-to-shot separation, we reveal the conditions for ultrafast writing and the fastest possible restoration of magnetic bits. It is shown that although magnetic writing launched by the first shot is completed after 100 ps, a reliable rewriting of the bit by the second shot requires separating the shots by at least 300 ps. Using two shots partially overlapping in space and minimally separated by 300 ps, we demonstrate an approach for GHz magnetic writing that can be scaled down to sizes below the diffraction limit.

Optical, electrochemical and third-order nonlinear optical studies of triphenylamine substituted zinc phthalocyanine

2016 ◽  
Vol 20 (08n11) ◽  
pp. 1173-1181 ◽  
Author(s):  
Narra Vamsi Krishna ◽  
Puliparambil Thilakan Anusha ◽  
S. Venugopal Rao ◽  
L. Giribabu
Keyword(s):  
Nonlinear Optical ◽  
Emission Spectra ◽  
Optical Emission ◽  
Soret Band ◽  
Laser Pulses ◽  
Zinc Phthalocyanine ◽  
Third Order ◽  
Time Resolved ◽  
Nlo Properties ◽  
Scan Data

Zinc phthalocyanine possessing triphenylamine at its peripheral position has been synthesized and its optical, emission, electrochemical and third-order nonlinear optical (NLO) properties were investigated. Soret band was broadened due to the presence of triphenylamine moiety. Electrochemical properties indicated that both oxidation and reduction processes were ring centered. Emission spectra were recorded in different solvents and the fluorescence yields obtained were in the range of 0.02–0.17 while the time-resolved fluorescence data revealed radiative lifetimes of typically few ns. Third-order NLO properties of this molecule have been examined using the Z-scan technique with picosecond (ps) and femtoseocnd (fs) pulses. Closed and open aperture Z-scan data were recorded with 2 ps/1 50 fs laser pulses at a wavelength of 800 nm and NLO coefficients were extracted from both the data. Our data clearly suggests the potential of this molecule for photonics applications.

Determination of Carbon Content in Steel Using Laser-Induced Breakdown Spectroscopy

1992 ◽  
Vol 46 (9) ◽  
pp. 1382-1387 ◽  
Author(s):  
J. A. Aguilera ◽  
C. Aragón ◽  
J. Campos
Keyword(s):  
Carbon Content ◽  
Matrix Effects ◽  
Sample Surface ◽  
Nitrogen Atmosphere ◽  
Laser Induced Breakdown Spectroscopy ◽  
Time Resolved ◽  
Breakdown Spectroscopy ◽  
Use Of Time ◽  
Laser Induced Breakdown

Laser-induced breakdown spectroscopy has been used to determine carbon content in steel. The plasma was formed by focusing a Nd:YAG laser on the sample surface. With the use of time-resolved spectroscopy and generation of the plasma in nitrogen atmosphere, a precision of 1.6% and a detection limit of 65 ppm have been obtained. These values are similar to those of other accurate conventional techniques. Matrix effects for the studied steels are reduced to a small slope difference between the calibration curves for stainless and nonstainless steels.

A methodology for nanosecond (or better) time resolved thermoreflectance imaging with coherence control of laser pulses

2013 ◽  
Vol 102 (20) ◽  
pp. 203112 ◽  
Author(s):  
Alok Soni ◽  
Vijay M. Sundaram ◽  
Sy-Bor Wen
Keyword(s):  
Laser Pulses ◽  
Time Resolved
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