Nonlinear Mechanisms in Carbon-Black Suspension in a Limiting Geometry

1997 ◽  
Vol 479 ◽  
Author(s):  
Francois Fougeanet ◽  
Jean-Claude Fabre
Keyword(s):  
Carbon Black ◽  
Optical Limiting ◽  
Plasma Emission ◽  
Time Resolved ◽  
Pump Probe ◽  
Limiting Behavior ◽  
Plasma Effects ◽  
Probe Experiment ◽  
Probe Transmission ◽  
Pump Probe Experiment

AbstractAlthough Carbon-Black suspensions (CBS) have been studied extensively for optical limiting applications, the microscopic mechanisms responsible for their limiting behavior still remain unclear. To study the mechanisms leading to the nonlinearity, we have performed a pump-probe experiment coupled with plasma emission measurements. Time resolved probe transmission have permitted to differentiate bubbles from plasma effects in the case of Carbon-Black in CS2. Other effects are discussed in terms of limiting performance.

Investigation of Optical Limiting Mechanism in Multiwalled Carbon Nanotubes

1999 ◽  
Vol 597 ◽  
Author(s):  
X. Sun ◽  
Y. N. Xiong ◽  
P. Chen ◽  
J. Y. Lin ◽  
W. Ji ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Black ◽  
Multiwalled Carbon Nanotubes ◽  
Optical Limiting ◽  
Nonlinear Scattering ◽  
Multiwalled Carbon ◽  
Time Resolved ◽  
Pump Probe ◽  
Limiting Behavior ◽  
Energy Dependent

AbstractWe report an investigation into the mechanism responsible for the optical limiting behavior in multiwalled carbon nanotubes. We conducted energy-dependent transmission measurements, picosecond time-resolved pump-probe, and nonlinear scattering experiments at 532-nm wavelength on multiwalled carbon nanotube suspension. For comparison, C60-toluene solution and carbon black suspension were also studied in the same experiments. The similarities that we observed between the multiwalled carbon nanotubes and carbon black suspension suggest that nonlinear scattering, which is known to be responsible for the limiting action in carbon black suspension, should play an important role in the limiting effect in multiwalled carbon nanotubes.

scholarly journals Tracing orbital images on ultrafast time scales

Science ◽  
2021 ◽  
pp. eabf3286
Author(s):  
R. Wallauer ◽  
M. Raths ◽  
K. Stallberg ◽  
L. Münster ◽  
D. Brandstetter ◽  
...  
Keyword(s):  
Momentum Space ◽  
Real Space ◽  
Space Distribution ◽  
Time Resolved ◽  
Pump Probe ◽  
High Laser ◽  
Probe Experiment ◽  
Electron Distributions ◽  
Space Dynamics ◽  
Pump Probe Experiment

Frontier orbitals determine fundamental molecular properties such as chemical reactivities. Although electron distributions of occupied orbitals can be imaged in momentum space by photoemission tomography, it has so far been impossible to follow the momentum-space dynamics of a molecular orbital in time, for example through an excitation or a chemical reaction. Here, we combined time-resolved photoemission using high laser harmonics and a momentum microscope to establish a tomographic, femtosecond pump-probe experiment of unoccupied molecular orbitals. We measured the full momentum-space distribution of transiently excited electrons, connecting their excited-state dynamics to real-space excitation pathways. Because in molecules this distribution is closely linked to orbital shapes, our experiment may in the future offer the possibility to observe ultrafast electron motion in time and space.

Optical Limiting With Neutral Nickel Dithiolene Complexes

1999 ◽  
Vol 597 ◽  
Author(s):  
W. L. Tan ◽  
W. Ji ◽  
J. L. Zuo ◽  
J. F. Bai ◽  
X. Z. You ◽  
...  
Keyword(s):  
Benzene Solution ◽  
Excited State Absorption ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Optical Limiting ◽  
Linear Absorption ◽  
Time Resolved ◽  
Pump Probe ◽  
Limiting Behavior ◽  
Picosecond Pulses

AbstractWe report an investigation of optical-limiting behavior in two neutral nickel complexes with multi-sulfur 1,2 dithiolene ligands, [Ni(medt)2] I (medt = 5,6-dihydro-6-methyl-1,4-dithiin-2,3- dithiolate) and [Ni(phdt)2] 2 (phdt = 5,6-dihydro-5-phenyl-l,4-dithiin-2,3-dithiolate) in benzene solution. The fluence-dependent transmission of the complexes was observed with nanosecond and picosecond laser pulses at 532-nm wavelength. The limiting thresholds of the complexes were ˜0.3 J/cm2, when measured with the picosecond pulses. Both picosecond time-resolved pump-probe and Z-scan measurement revealed that the limiting effects should originate from excited-state absorption and refraction. The transparency window (400˜900 nm), observed in the linear absorption spectra of the complexes, indicated that their limiting response should cover a wider range than those of fullerenes and phthalocyanines.

scholarly journals Effective data collection and refinement of pertubated structures

2014 ◽  
Vol 70 (a1) ◽  
pp. C1750-C1750
Author(s):  
Pascal Parois ◽  
Richard Cooper
Keyword(s):  
Excited State ◽  
Data Collection ◽  
Least Squares ◽  
Time Resolved ◽  
Pump Probe ◽  
Partial Data ◽  
Mixed Oxidation ◽  
Probe Experiment ◽  
Pump Probe Experiment

Approaches to determining the influence of individual measurements on the precision of crystallographic least squares parameters have been known for a long while.[1] Situations in which the precision of a single parameter (or linear combination of parameters) is critical can include: determination of novel bond lengths; refinement of site occupancies in mixed metal or mixed oxidation state systems; determination of the fraction of excited state molecules in a time-resolved pump-probe experiment. Such calculations are easily applicable to point-detector instruments, where individual influential reflections could be remeasured one-by-one. However, on a modern area detector instrument many reflections are measured on one frame and therefore some consideration of the appropriate strategy of reciprocal space scans is permitted to allow a more efficient use of the instrument. The highly influential partial data collection is then feed into an appropriate refinement model. Occupancies in mixed-metal or mixed-oxidation state systems and fractions and positions of excited state molecules during a time-resolved pump-probe experiment can be determined using direct refinement of the perturbation of the structure from the ground state. Re-factoring to modern Fortran of the Crystals software is in progress to allow the implementation of new algorithms such as a difference refinement.[2] We present an analysis of diffractometer strategy selection to prioritize scans which give the best improvement in specific least-squares parameters and a novel algorithm for the refinement of the partial data using crystals.

Collinear pump probe experiment, novel approach to ultrafast spectroscopy

1999 ◽  
Vol 68 (4) ◽  
pp. 689-692 ◽  
Author(s):  
B. Bousquet ◽  
L. Canioni ◽  
J. Plantard ◽  
L. Sarger
Keyword(s):  
Ultrafast Spectroscopy ◽  
Pump Probe ◽  
Novel Approach ◽  
Probe Experiment ◽  
Pump Probe Experiment

scholarly journals Probing calculatedO2+potential-energy curves with an XUV-IR pump-probe experiment

2015 ◽  
Vol 91 (4) ◽  
Author(s):  
Philipp Cörlin ◽  
Andreas Fischer ◽  
Michael Schönwald ◽  
Alexander Sperl ◽  
Tomoya Mizuno ◽  
...  
Keyword(s):  
Potential Energy ◽  
Potential Energy Curves ◽  
Pump Probe ◽  
Probe Experiment ◽  
Pump Probe Experiment
Sign in / Sign up

Export Citation Format

Share Document