Two-Photon Absorption And Time-Resolved Stimulated Emission Depletion Spectroscopy Of A New Push-Pull Fluorene Derivative

Author(s):  
Kevin D. Belfield ◽  
Mykhailo V. Bondar ◽  
Alma R. Morales ◽  
Xiling Yue ◽  
Gheorghe Luchita ◽  
...  
ChemPhysChem ◽  
2012 ◽  
Vol 13 (15) ◽  
pp. 3481-3491 ◽  
Author(s):  
Kevin D. Belfield ◽  
Mykhailo V. Bondar ◽  
Alma R. Morales ◽  
Xiling Yue ◽  
Gheorghe Luchita ◽  
...  

Plasma ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 145-171
Author(s):  
Kristaq Gazeli ◽  
Guillaume Lombardi ◽  
Xavier Aubert ◽  
Corinne Y. Duluard ◽  
Swaminathan Prasanna ◽  
...  

Recent developments in plasma science and technology have opened new areas of research both for fundamental purposes (e.g., description of key physical phenomena involved in laboratory plasmas) and novel applications (material synthesis, microelectronics, thin film deposition, biomedicine, environment, flow control, to name a few). With the increasing availability of advanced optical diagnostics (fast framing imaging, gas flow visualization, emission/absorption spectroscopy, etc.), a better understanding of the physicochemical processes taking place in different electrical discharges has been achieved. In this direction, the implementation of fast (ns) and ultrafast (ps and fs) lasers has been essential for the precise determination of the electron density and temperature, the axial and radial gradients of electric fields, the gas temperature, and the absolute density of ground-state reactive atoms and molecules in non-equilibrium plasmas. For those species, the use of laser-based spectroscopy has led to their in situ quantification with high temporal and spatial resolution, with excellent sensitivity. The present review is dedicated to the advances of two-photon absorption laser induced fluorescence (TALIF) techniques for the measurement of reactive species densities (particularly atoms such as N, H and O) in a wide range of pressures in plasmas and flames. The requirements for the appropriate implementation of TALIF techniques as well as their fundamental principles are presented based on representative published works. The limitations on the density determination imposed by different factors are also discussed. These may refer to the increasing pressure of the probed medium (leading to a significant collisional quenching of excited states), and other issues originating in the high instantaneous power density of the lasers used (such as photodissociation, amplified stimulated emission, and photoionization, resulting to the saturation of the optical transition of interest).


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7744
Author(s):  
Ye Tian ◽  
Ming Wei ◽  
Lijun Wang ◽  
Yuankai Hong ◽  
Dan Luo ◽  
...  

Due to the unique advantages of two-photon technology and time-resolved imaging technology in the biomedical field, attention has been paid to them. Gold clusters possess excellent physicochemical properties and low biotoxicity, which make them greatly advantageous in biological imaging, especially for in vivo animal imaging. A gold nanocluster was coupled with dihydrolipoic acid to obtain a functionalized nanoprobe; the material displayed significant features, including a large two-photon absorption cross-section (up to 1.59 × 105 GM) and prolonged fluorescence lifetime (>300 ns). The two-photon and time-resolution techniques were used to perform cell imaging and in vivo imaging.


2018 ◽  
Vol 148 (13) ◽  
pp. 134312 ◽  
Author(s):  
T. A. Masters ◽  
N. A. Robinson ◽  
R. J. Marsh ◽  
T. S. Blacker ◽  
D. A. Armoogum ◽  
...  

2019 ◽  
Vol 15 ◽  
pp. 2438-2446 ◽  
Author(s):  
Alessandro Iagatti ◽  
Baihao Shao ◽  
Alberto Credi ◽  
Barbara Ventura ◽  
Ivan Aprahamian ◽  
...  

In this work we apply a combination of steady state and time resolved luminescence and absorption spectroscopies to investigate the excited-state dynamics of a recently developed molecular photoswitch, belonging to the hydrazone family. The outstanding properties of this molecule, involving fluorescence toggling, bistability, high isomerization quantum yield and non-negligible two-photon absorption cross section, make it very promising for numerous applications. Here we show that the light induced Z/E isomerization occurs on a fast <1 ps timescale in both toluene and acetonitrile, while the excited state lifetime of the Z-form depends on solvent polarity, suggesting a partial charge transfer nature of its low lying excited state. Time-resolved luminescence measurements evidence the presence of a main emission component in the 500–520 nm spectral range, attributed to the Z-isomer, and a very short living blue-shifted emission, attributed to the E-isomer. Finally, transient absorption measurements performed upon far-red excitation are employed as an alternative method to determine the two-photon absorption cross-section of the molecule.


2009 ◽  
Vol 113 (20) ◽  
pp. 7101-7106 ◽  
Author(s):  
Kevin D. Belfield ◽  
Mykhailo V. Bondar ◽  
Ciceron O. Yanez ◽  
Florencio E. Hernandez ◽  
Olga V. Przhonska

2019 ◽  
Vol 28 (01) ◽  
pp. 1950003 ◽  
Author(s):  
Yaochuan Wang ◽  
Yizhuo Wang ◽  
Guiqiu Wang ◽  
Dajun Liu

A series of branched styryl derivatives based on 1,3,5-triazine were studied by nonlinear optical property measurement, degenerated pump-probe, and time-resolved fluorescence anisotropy methods to elucidate the two-photon absorption (TPA) properties and intramolecular interactions between branches. Significant enhancement of the TPA cross-section was observed in multi-branched derivatives. The anisotropy of multi-branched compounds shows faster decay and small residual values, indicating strong intramolecular interactions between branches, which further confirmed the TPA enhancement mechanism.


Sign in / Sign up

Export Citation Format

Share Document