Microwave Synthesis and Up-Conversion Properties of SHG-Active α-(La, Er)(IO) Nanocrystals.

Pure α-La(IO) and α-LaEr(IO) nanocrystals were synthesized by a microwave-assisted hydrothermal method leading to a reaction yield of 87 ± 4%. Electron microscopy and dynamic light scattering characterizations provide evidence for the formation of nanocrystals with an average size of 45 ± 10 nm for α-La(IO) and 55 ± 10 nm for α-LaEr(IO). When dispersed in ethylene glycol, the nanocrystal suspensions exhibit second-harmonic generation under near-infrared excitations at 800 and 980 nm whereas additional photoluminescence by up-conversion is simultaneously observed in the case of α-LaEr(IO) nanocrystals.

Nonlinear optical susceptibility of two-dimensional WS measured by hyper Rayleigh scattering: erratum.

This erratum corrects errors in the expressions for ⟨β⟩ and fitted form of I and a consequent data point in Fig. 4 of a recent Letter [Opt. Lett.

Bismuth ferrite dielectric nanoparticles excited at telecom wavelengths as multicolor sources by second, third, and fourth harmonic generation.

We demonstrate the simultaneous generation of second, third, and fourth harmonics from a single dielectric bismuth ferrite nanoparticle excited using a telecom fiber laser at 1560 nm. We first characterize the signals associated with different nonlinear orders in terms of spectrum, excitation intensity dependence, and relative signal strengths. Successively, on the basis of the polarization-resolved emission curves of the three harmonics, we discuss the interplay of susceptibility tensor components at different orders and show how polarization can be used as an optical handle to control the relative frequency conversion properties.

Nonlinear optical susceptibility of two-dimensional WS measured by hyper Rayleigh scattering.

Hyper Rayleigh scattering (HRS) was used to measure the second-order nonlinear susceptibility, χ, for liquid exfoliated WS monolayers. To the best of our knowledge, it is the first reported application of the HRS technique to assess the bulk-like χ of a two-dimensional (2D) material. The concentration-dependent HRS signal indicated a 4.

Multi-Order Investigation of the Nonlinear Susceptibility Tensors of Individual Nanoparticles.

We use Hyper Rayleigh Scattering and polarization resolved multiphoton microscopy to investigate simultaneously the second and third-order nonlinear response of Potassium Niobate and Bismuth Ferrite harmonic nanoparticles. We first derive the second-to-third harmonic intensity ratio for colloidal ensembles and estimate the average third-order efficiency of these two materials. Successively, we explore the orientation dependent tensorial response of individual nanoparticles fixed on a substrate.