Pulsewidth dependence of time‐resolved two‐photon absorption with picosecond pump–probe excitation

1992 ◽  
Vol 71 (5) ◽  
pp. 2102-2105 ◽  
Author(s):  
Yasuo Tomita ◽  
Masa‐aki Shibata ◽  
Johan Bergquist
Keyword(s):  
Photon Absorption ◽  
Time Resolved ◽  
Pump Probe ◽  
Two Photon Absorption ◽  
Two Photon

Ultrafast pump-probe and time-resolved fluorescence anisotropy study of the intramolecular interaction of branched styryl derivatives based on 1,3,5-triazine

2019 ◽  
Vol 28 (01) ◽  
pp. 1950003 ◽  
Author(s):  
Yaochuan Wang ◽  
Yizhuo Wang ◽  
Guiqiu Wang ◽  
Dajun Liu
Keyword(s):  
Fluorescence Anisotropy ◽  
Intramolecular Interaction ◽  
Intramolecular Interactions ◽  
Photon Absorption ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Pump Probe ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Property Measurement

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.

Investigation of nondegenerate two-photon absorption in common fluorescent dyes

2018 ◽  
Vol 27 (03) ◽  
pp. 1850027 ◽  
Author(s):  
Huantian Xu ◽  
Shu Chen ◽  
Kaijun Mu ◽  
Junqiao Wang ◽  
Yongzhi Tian ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Fluorescent Dyes ◽  
Photon Absorption ◽  
Time Resolved ◽  
Pump Probe ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Essential State ◽  
Good Agreement

The nondegenerate two-photon excited fluorescence (ND-TPEF) and nondegenerate two-photon absorption (ND-TPA) cross-sections of two common fluorescent dyes were investigated using the femtosecond pump-probe technique at several wavelength combinations. Time-resolved and laser intensity dependent fluorescence revealed that the fluorescence was originated from the ND-TPA effect. Experimental ND-TPA cross-section exhibited larger values than corresponding degenerate two-photon absorption case. Additionally, an improved essential-state model involving multiple TPA excited states was proposed to evaluate the TPA cross-section of organic molecules, which showed good agreement with experimental results. This study indicates that the investigated fluorescent dyes would play important roles in multicolor two-photon imaging.

Nonlinear optical property and ultrafast response of a two-photon photopolymerization initiator based on dibenzothiophene

2017 ◽  
Vol 26 (04) ◽  
pp. 1750048 ◽  
Author(s):  
Yaochuan Wang ◽  
Dajun Liu ◽  
Yizhuo Wang ◽  
Guiqiu Wang ◽  
Xiaoqiang Yu
Keyword(s):  
Cross Section ◽  
Fluorescence Emission ◽  
Photon Absorption ◽  
Time Resolved ◽  
Pump Probe ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Uv Visible ◽  
Two Photon Fluorescence ◽  
Photon Fluorescence

A dibenzothiophene-based two-photon photopolymerization (TPP) initiator named E,E-1,4-bis[3-vinyl-dibenzothiophene]-2,5-dimethoxybenzene (VBPMOB) with intense two-photon fluorescence (TPF) was investigated by UV–visible, fluorescence, pump–probe and time-resolved fluorescence spectroscopies. The maximum two-photon absorption (TPA) cross-section of VBPMOB in DMF was determined to be 274[Formula: see text]GM. In addition, the TPA cross-section at 800[Formula: see text]nm was 230[Formula: see text]GM, which is the most commonly used wavelength for TPP. The ultrafast spectra result indicated that after excitation, the VBPMOB molecule will first undergo a fast internal conversion process to form an intramolecular charge transfer (ICT) state with a certain width followed by relaxation of the ICT state with fluorescence emission.

scholarly journals Two-Photon Time-Gated In Vivo Imaging of Dihydrolipoic-Acid-Decorated Gold Nanoclusters

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7744
Author(s):  
Ye Tian ◽  
Ming Wei ◽  
Lijun Wang ◽  
Yuankai Hong ◽  
Dan Luo ◽  
...  
Keyword(s):  
In Vivo Imaging ◽  
Gold Nanoclusters ◽  
Photon Absorption ◽  
Gold Nanocluster ◽  
Time Resolved ◽  
Dihydrolipoic Acid ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Time Resolved Imaging

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.

scholarly journals Ultrafast processes triggered by one- and two-photon excitation of a photochromic and luminescent hydrazone

2019 ◽  
Vol 15 ◽  
pp. 2438-2446 ◽  
Author(s):  
Alessandro Iagatti ◽  
Baihao Shao ◽  
Alberto Credi ◽  
Barbara Ventura ◽  
Ivan Aprahamian ◽  
...  
Keyword(s):  
Excited State ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Transient Absorption ◽  
Solvent Polarity ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Time Resolved ◽  
Two Photon Absorption ◽  
Two Photon

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.

Enhancement of two photon absorption properties and intersystem crossing by charge transfer in pentaaryl boron-dipyrromethene (BODIPY) derivatives

2016 ◽  
Vol 18 (19) ◽  
pp. 13546-13553 ◽  
Author(s):  
B. Küçüköz ◽  
G. Sevinç ◽  
E. Yildiz ◽  
A. Karatay ◽  
F. Zhong ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Photon Absorption ◽  
Intersystem Crossing ◽  
Absorption Properties ◽  
Pump Probe ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Boron Dipyrromethene ◽  
Probe Spectroscopy

Indication of charge transfer and an intersystem crossing mechanism for the B4 compound by using ultrafast pump probe spectroscopy.

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