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Hybrid organic–inorganic metal halides have emerged as highly promising materials for a wide range of applications in optoelectronics. Incorporating chiral organic molecules into metal halides enables the extension of their unique optical and electronic properties to chiral optics. By using chiral (R)‐ or (S)‐methylbenzylamine (R‐/S‐MBA) as the organic component, we synthesized chiral hybrid copper halides, (R‐/S‐MBA)2CuCl4, and investigated their optical activity. Thin films of this material showed a record anisotropic g‐factor as high as approximately 0.06. We discuss the origin of the giant optical activity observed in (R‐/S‐MBA)2CuCl4 by theoretical modeling based on density functional theory (DFT) and demonstrate highly efficient second harmonic generation (SHG) in these samples. Our study provides insight into the design of chiral materials by structural engineering, creating a new platform for chiral and nonlinear photonic device applications of the chiral hybrid copper halides. [ABSTRACT FROM AUTHOR]

Abstract: Nonlinear optical absorption properties of two chiral polybinaphthyls with the same backbone but different electron acceptor hydroxyl and octoxy were studied in tetrahydrofuran solution. When excited by 100 fs 800 nm laser pulses, the up-converted fluorescence were observed and the intensities related to the different input irradiances were measured to confirm the two-photon excited fluorescence. The two-photon absorption coefficients were obtained as 4.82 cm GW−1 and 12.36 cm GW−1 with 100 fs pulses at 800 nm for two polymers, respectively. Under the excitation of 532 nm 38 ps pulse, it was found that the polymer with the side-chain of hydroxyl showed saturable absorption while the polymer with the side-chain of octoxy presented reverse saturable absorption. Their different nonlinear absorption behavior resulted from the fact that the ground-state absorption cross-section in the latter polymer was about 10 times larger than that of the former polymer while the excited-state absorption cross-section represented similar. [Copyright &y& Elsevier]

Abstract: The nonlinear optical properties of a series of azobenzene liquid-crystalline materials, which have different side-chain lengths in their molecular structure from one to another, were investigated using Z-scan method under picosecond pulse laser at 532nm, 1064nm and CW 488nm excitation. The mechanism accounting for the process of nonlinear refraction was discussed under different laser excitations. The polymer films possess very large nonlinear refraction at all the three different laser excitations. Especially, the nonlinear refractive index becomes larger as the length of side-chain, where azobenzene group is contained, increases under pulse excitation at 1064nm. [Copyright &y& Elsevier]

Abstract: The nonlinear optical properties of an azo-based dye were investigated using Z-scan technique employing 38ps pulses at 532 and 1064nm, and 6ns laser pulses at 532nm. Large nonlinear absorption and nonlinear refraction were observed at both ps and ns 532nm in the azoic dye. When excited at ps 1064nm, this dye displayed a large two-photon absorption cross-section (σ 2=1810GM). Meanwhile, the optical nonlinearity mechanism was discussed in terms of molecular structure, excitation wavelength, and pulse width. [ABSTRACT FROM AUTHOR]

Abstract: The nonlinear optical properties and photoinduced anisotropy of an azobenzene ionic liquid–crystalline polymer were investigated. The single beam Z-scan measurement showed the polymer film possessed a value of nonlinear refractive index n 2 =−1.07×10−9 cm2/W under a picosecond 532nm excitation. Photoinduced anisotropy in the polymer was studied through dichroism and photoinduced birefringence. A photoinduced birefringence value Δn ∼10−2 was achieved in the polymer film. The mechanism for the nonlinear optical response and the physical process of photoinduced anisotropy in the polymer were discussed. [Copyright &y& Elsevier]

The nonlinear optical properties and photoinduced anisotropy of a novel stilbene-containing fluorinated polyimide were investigated. Large macroscopic second-order optical nonlinearity (d 33 =35.4pm/V) was obtained in a poled thin film using the Maker fringe method. A nonlinear absorption coefficient (β) of 0.65×10−5 cm/W and third-order nonlinear refractive index (n 2) of −1.13×10−10 cm2/W were determined by Z-scan measurements. Photoinduced birefringence (Δn) of 1.02×10−2 was observed using a continuous Nd:YAG laser at 532nm as pump light and a continuous diode laser at 650nm as probe light. [Copyright &y& Elsevier]

Keywords: chirality; circular dichroism; hybrid copper halides; nonlinear optics; second harmonic generation EN chirality circular dichroism hybrid copper halides nonlinear optics second harmonic generation 21262 21262 1 09/16/21 20210920 NES 210920 Because the interference is not considered, formula (4) in this Communication is not really applicable for the I d SB eff sb i estimation of the hybrid metal halide thin film. Chirality, circular dichroism, hybrid copper halides, nonlinear optics, second harmonic generation. [Extracted from the article]

Chirality, circular dichroism, hybrid copper halides, nonlinear optics, second harmonic generation Keywords: chirality; circular dichroism; hybrid copper halides; nonlinear optics; second harmonic generation EN chirality circular dichroism hybrid copper halides nonlinear optics second harmonic generation 21094 21094 1 09/16/21 20210920 NES 210920 Because the interference is not considered, formula (4) in this Communication is not really applicable for the I d SB eff sb i estimation of the hybrid metal halide thin film. [Extracted from the article]