Surface area-dependent second harmonic generation from silver nanorods

2016 ◽  
Vol 18 (33) ◽  
pp. 23215-23219 ◽  
Author(s):  
Hoang Minh Ngo ◽  
Thanh Tuyen Luong ◽  
Isabelle Ledoux-Rak

We have evidenced strong first hyperpolarizabilities in silver nanorods (AgNRs) for the first time. The first hyperpolarizability β values linearly depend on the surface area of AgNRs.

2016 ◽  
Vol 18 (4) ◽  
pp. 3352-3356 ◽  
Author(s):  
Hoang Minh Ngo ◽  
Phuong Phong Nguyen ◽  
Isabelle Ledoux-Rak

Gold nanoparticles display exceptionally strong β values. We demonstrated that the first hyperpolarizability (β) strongly depends on surface area of gold nanoparticles.


2012 ◽  
Vol 26 (29) ◽  
pp. 1250148
Author(s):  
FEI FEI WANG ◽  
JIAN MEI LIU ◽  
XIAO YUAN DENG

In this paper, for the first time, we consider theoretically all the potential orientations of dipoles for second harmonic generation (SHG) under crystallized type I collagen fiber. With high numerical aperture ( NA = 14), the effect of dipole orientation angle Φ on the SHG intensity, on the maximum SHG emergence angles (θ max , φ max ) and the action of these dipole sources on the ratio of forward to backward (F/B) SHG have been studied under different cases of fibrils diameter d1 and the QPM order (m, l) in the crystallized collagen fiber, and it is found that the influential patterns of the same Φ on SHG at different fibrils diameter d1 and the QPM order (m, l) are different. The dipoles arrangement is related to the characteristic changes in biological tissue so that our work may provide a helpful theoretical tool for pathological status detecting.


2020 ◽  
Author(s):  
Jakob Seibert ◽  
Benoît CHAMPAGNE ◽  
Stefan Grimme ◽  
Marc de Wergifosse

<div>Chains of amino acids can model endogenous biotags for applications in second harmonic imaging microscopy. Such structures are inherently flexible which may strongly affect their structure-property relationship. Here, we explore quantum-mechanically the conformational space of a set of relatively large tryptophan-rich model peptides studied experimentally by Duboisset et al. [JPC B 2014 118]. This has become feasible because of the recently proposed meta-dynamics method based on efficient tight-binding (TB) quantum chemical calculations. The TB version of the simplified time-dependent density functional theory (sTD-DFT-xTB) method is used to evaluate the first hyperpolarizability. These new tools enable us to calculate nonlinear optical properties for systems with several thousand atoms and/or to screen large structure ensembles. First, we show that the first hyperpolarizability of these systems is dominated by the indole chromophore in the tryptophan residues. Their relative orientation mostly determines the global β tensor and affects the static first hyperpolarizability response drastically. The results underline the importance of finding low-energy conformers for modeling the first hyperpolarizabilities of flexible molecules. Additionally, we compare calculated and extrapolated experimental static first hyperpolarizabilities. <br></div><div>We conclude that the sTD-DFT-xTB method is capable of providing reliable second-harmonic generation values for tryptophan-rich systems at a fraction of the computational cost of the commonly used TD-DFT/TD-HF levels of theory.</div>


2019 ◽  
Vol 2 (2) ◽  
pp. 49 ◽  
Author(s):  
Mehdi Alizadeh ◽  
Masood Ghotbi ◽  
Pablo Loza-Alvarez ◽  
David Merino

Polarization sensitive second harmonic generation (pSHG) microscopy is an imaging technique able to provide, in a non-invasive manner, information related to the molecular structure of second harmonic generation (SHG) active structures, many of which are commonly found in biological tissue. The process of acquiring this information by means of pSHG microscopy requires a scan of the sample using different polarizations of the excitation beam. This process can take considerable time in comparison with the dynamics of in vivo processes. Fortunately, single scan polarization sensitive second harmonic generation (SS-pSHG) microscopy has also been reported, and is able to generate the same information at a faster speed compared to pSHG. In this paper, the orientation of second harmonic active supramolecular assemblies in starch granules is obtained on by means of pSHG and SS-pSHG. These results are compared in the forward and backward directions, showing a good agreement in both techniques. This paper shows for the first time, to the best of the authors’ knowledge, data acquired using both techniques over the exact same sample and image plane, so that they can be compared pixel-to-pixel.


1993 ◽  
Vol 328 ◽  
Author(s):  
Eric Hendrickx ◽  
Thierry Verbiest ◽  
Koen Clays ◽  
Celest Samyn ◽  
Andre Persoons

ABSTRACTIn this paper some of the more important Hyper Rayleigh Scattering (HRS) Measurements performed in our laboratory are reviewed. The results of experiments conducted on polymers, the protein Bacteriorhodopsin, retinal derivatives and octopoles are presented. Basic HRS theory, along with a brief description of the HRS set-up, is also included.We demonstrate that the experimental simplicity of HRS allows for an accurate determination of the first hyperpolarizability of molecules that could not have been measured by the more traditional Electric Field Induced Second Harmonic Generation (EFISHG) technique.


2019 ◽  
Vol 48 (36) ◽  
pp. 13529-13535 ◽  
Author(s):  
Qi Wu ◽  
Xian Liu ◽  
Fei Liang ◽  
Siran Xu ◽  
Hongbing Pi ◽  
...  

This study reports, for the first time, the second-harmonic generation (SHG) property of Pb7F12Cl2 as a promising infrared nonlinear optical (NLO) material.


2016 ◽  
Vol 45 (43) ◽  
pp. 17431-17438 ◽  
Author(s):  
D. Espa ◽  
L. Pilia ◽  
L. Marchiò ◽  
F. Artizzu ◽  
G. Di Carlo ◽  
...  

A film of [Pd(Dod2pipdt)(dmit)] incorporated into a polymethylmethacrylate matrix, showing a good second-harmonic generation, has been prepared for the first time in the class of dithione–dithiolate 2ndorder NLO-chromophores.


2020 ◽  
Vol 102 (24) ◽  
Author(s):  
I. A. Kolmychek ◽  
I. V. Malysheva ◽  
V. B. Novikov ◽  
A. P. Leontiev ◽  
K. S. Napolskii ◽  
...  

Author(s):  
Guillaume Le Breton ◽  
Oriane Bonhomme ◽  
Pierre-Francois Brevet ◽  
Emmanuel Benichou ◽  
Claire Loison

Surface Second-harmonic generation (S-SHG) experiments provide a unique approach to probe interfaces. One important issue for S-SHG is how to interpret the S-SHG intensities at the molecular level. Established frameworks...


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