Size Dependence of Second Harmonic Generation in Cdse Nanocrystals

1999 ◽  
Vol 571 ◽  
Author(s):  
M. Jacobsohn ◽  
U. Banin

ABSTRACTSecond Harmonic Generation in CdSe nanocrystal quantum dots is observed by Hyper-Rayleigh scattering. We use a Ti-Sapphire femtosecond laser at 820 nm to induce the nonlinear optical response of the nanocrystals in solution. The unit cell normalized second harmonic coefficient βn, shows a substantial systematic enhancement in small sizes. The observed size dependence of the second harmonic generation process, is explained assuming two contributions. The first is a bulk-like contribution, from the non-centrosymmetric nanocrystal core, and the second, a contribution from the particle surface. The latter contribution is most significant in small nanocrystals with a substantial proportion of surface atoms.

2011 ◽  
Vol 284 (5) ◽  
pp. 1401-1404 ◽  
Author(s):  
Michaël Delqué ◽  
Gil Fanjoux ◽  
Simon-Pierre Gorza ◽  
Marc Haelterman

2018 ◽  
Vol 43 (14) ◽  
pp. 3236 ◽  
Author(s):  
Haigang Liu ◽  
Xiaohui Zhao ◽  
Hui Li ◽  
Yuanlin Zheng ◽  
Xianfeng Chen

2009 ◽  
Vol 152-153 ◽  
pp. 508-511 ◽  
Author(s):  
I.A. Kolmychek ◽  
T.V. Murzina ◽  
S. Fourier ◽  
J. Wouters ◽  
V.K. Valev ◽  
...  

The films containing core (shell) γ-Fe2O3 (Au) nanoparticles that possess the plasmon resonance at the wavelength 550 nm are prepared. The second harmonic generation in these structures is shown to be diffuse and depolarized, that is typical for the hyper-Rayleigh scattering.. The studies of the magnetization-induced second harmonic generation shows that the ratio of the magnetic to nonmagnetic components of the hyperpolarizability of a single nanoparticle, γM/γ0 ~ 0.4 in the field of about 3 kOe.


2008 ◽  
Vol 16 (19) ◽  
pp. 14496 ◽  
Author(s):  
A. Massaro ◽  
V. Tasco ◽  
M. T. Todaro ◽  
R. Cingolani ◽  
M. De Vittorio ◽  
...  

2010 ◽  
Vol 81 (5) ◽  
Author(s):  
Sviatlana Viarbitskaya ◽  
Valery Kapshai ◽  
Peter van der Meulen ◽  
Tony Hansson

2019 ◽  
Author(s):  
Franz Geiger ◽  
Paul E. Ohno ◽  
HanByul Chang ◽  
Austin P. Spencer ◽  
Mavis D. Boamah ◽  
...  

<p>We report ionic strength-dependent phase shifts in second harmonic generation (SHG) signals from charged interfaces that verify a recent model in which dispersion between the fundamental and second harmonic beams modulates observed signal intensities. We show how phase information can be used to unambiguously separate the chi(2) and interfacial potential-dependent chi(3) terms that contribute to the total signal and provide a path to test primitive ion models and mean field theories for the electrical double layer with experiments to which theory must conform. Finally, we demonstrate the new method on supported lipid bilayers and comment on the ability of our new instrument to identify hyper-Rayleigh scattering contributions to common homodyne SHG measurements in reflection geometries.</p>


2020 ◽  
Author(s):  
Guan Gui ◽  
Nathan Brooks ◽  
Henry Kapteyn ◽  
Margaret Murnane ◽  
Chen-Ting Liao

Abstract Light with spatiotemporal orbital angular momentum (ST-OAM) is a recently discovered type of structured electromagnetic field with characteristic space-time spiral phase structure and transverse OAM. In this work, we present the first generation and characterization of the second-harmonic of ST-OAM pulses. By uncovering the conservation of transverse OAM in a second-harmonic generation process, where the space-time topological charge of the fundamental field is doubled along with the optical frequency, we establish a general nonlinear scaling rule— analogous to that describing the spatial topological charges associated with the conventional longitudinal OAM of light. Furthermore, we observe that the topology of a second-harmonic ST-OAM pulse can be modified by complex spatiotemporal astigmatism, giving rise to multiple phase singularities separated in space and time. Our finding thus confirms that a spatiotemporal phase winding, surrounding one or many phase singularities in space and time, can be interpreted as a new class of topological charge. Our study opens a new route for nonlinear conversion and scaling of light carrying ST-OAM with the potential for driving other secondary ST-OAM sources of electromagnetic fields, electron pulses, and beyond.


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