NEW ORGANIC NONLINEAR OPTICAL MATERIALS OF CINNAMYLIDENE-ACETOPHENONE DERIVATIVES

we have synthesised a series of new optically nonlinear organic materials of cinnamylidene-acetophenone derivatives which have large nonl inear optical susceptibilities and short cut-off wavelengths.

Optical Materials

Bluelightning Optics Co.,Ltd.(BOC)；The Featured of BOC's Nd:YLF:；Juhua Group Xinghua Crystal Materials Factory；Fujian Castech Crystals, Inc. (CASTECH)；Shanghai Fanguang Industry and Commerce Co.

Recent advances in F-containing iodate nonlinear optical materials

Metal iodates containing I(Ⅴ)with lone electron pairs in an asymmetric coordination geometry exhibit excellent second-harmonic generation(SHG)responses,wide transmission range and large band gaps.During the past ten years,metal iodates have been widely studied,and introducing large electronegative fluorine atoms into metal iodates has also attracted much attention.These F-containing iodates are different from pure iodates in terms of composition,symmetry and transmittance.Especially because oxide-fluoride heterolepic anion groups can exhibit interesting structure-directing properties,e.g.trans-and cis-directing properties,these F-containing iodates also have better structure designability.Therefore,in this review,we will review the research progress of F-containing iodates and address the effect of structure-directing properties of oxide-fluoride anions on the crystal structures of F-containing iodates.Since the valence of the central cations will greatly affect the distortions and configurations of the oxide-fluoride anion groups,these F-containing iodates will be classified and introduced according to the different valences of the central cations.

Salt-inclusion chalcogenides:Double functional moieties design strategy toward excellent nonlinear optical materials

Nonlinear optical(NLO)material are of great importance in converting the frequency to extend the laser spectrum in mid-and far-infrared(IR)regions where lasers operate poorly or are unavailable.However,the contradiction between large second-harmonic generation(SHG)intensity and wide band gap(E_(g))is a long-standing problem for IR NLO materials.To address the issue,metal chalcogenides have been successfully synthesized and developed excellent optical properties in the past few decades.As a newly discovered category of chalcogenides,salt-inclusion chalcogenides with distinctive structures and brilliant performances have been placed great expecta-tions to be a novel problem-solving.In this review,52 compounds in this thriving family are categorized via dimensions of host and guest parts,further discussing the relationships between their structures and NLO properties,as well as future perspectives of this family.

Nonlinear optical and optical limiting properties of new structures of organic nonlinear optical materials for photonic applications

The nonlinear optical （NLO） and optical limiting （OL） properties of three new structures of organic NLO guest host Poly（N-vinylcarbozole）/disperse orange 3 （PVK/DO3）, PVK/disperse orange 13 （PVK/DO13）. and PVK/disperse orange 25 （PVK/DO25） as a solution at different concentrations and as a thin-film sample are studied using continuous wave z-scan system at 532 nm. The open-aperture z-scan data of the NLO materials in the solution and thin-film samples displayed two-photon and saturable absorptions, respectively. The PVK/DO13 exhibites the largest and best values of the nonlinearities, such as n2, β, X（3） compared with those of PVK/DO3 and PVK/DO25. This nonlinearity increases as the concentration increases. Tile results indicate that these NLO materials are good candidates for optical switching and OL devices.

Recent Progresses of UV Nonlinear Optical Materials

Ultraviolet(UV)nonlinear optical(NLO)crystal materials are hailed as the"chip"of the optoelectronic industry for they play a unique and crucial role in many newly developed scientific and technological applications.At present,due to the relatively single frequency doubling gene types of traditional NLO materials,the service performance of UV NLO materials is fundamentally restricted.Therefore,there is an urgent need to develop new synthesis methods,search for novel functional groups,expand new UV NLO materials systems,screen new high-performance crystals,and then break through performance bottlenecks.Herein,we review the recent progresses on UV NLO crystal materials.Furthermore,we prospect that these recently developed approaches will continuously extend their advantages in developing superior UV NLO materials in the near future.

Flexible,robust and highly efficient broadband nonlinear optical materials based on graphene oxide impregnated polymer sheets

We report a simple solution-processed method for the fabrication of low-cost,flexible optical limiting materials based on graphene oxide(GO) impregnated polyvinyl alcohol(PVA) sheets.Such GO–PVA composite sheets display highly efficient broadband optical limiting activities for femtosecond laser pulses at 400,800,and 1400 nm with very low limiting thresholds.Femtosecond pump–probe measurement results revealed that nonlinear absorption played an important role for the observed optical limiting activities.High flexibility and efficient optical limiting activities of these materials allow these composite sheets to be attached to nonplanar optical sensors in order to protect them from light-induced damage.

Faraday effect measurements of holmium oxide(Ho2O3) ceramics-based magneto-optical materials

Faraday effect measurements of holmium oxide(Ho_2O_3) ceramics-based magneto-optical materials, highly potential material candidates for high-energy laser Faraday isolators, are presented in this paper. Temperature dependence of the Verdet constant of nondoped Ho_2O_3 ceramics was measured for temperatures 15–305 K at 1.064 μm wavelength.The Verdet constant dispersion for wavelengths 0.5–1 μm and 1.064 μm was measured for both nondoped Ho_2O_3 ceramics and Ho_2O_3 ceramics doped with terbium Tb3+(0.2 at. %) and cerium Ce3+(0.1 at. %) ions. The results suggest that the relatively low level of doping of Ho_2O_3 with these ions has no significant boosting impact on the Faraday effect. Therefore, other compositions of Ho_2O_3 ceramics-based magneto-optical materials, as well as various doping concentrations, should be further examined.

Research progress of cholesteric liquid crystals with broadband reflection characteristics in application of intelligent optical modulation materials

Cholesteric liquid crystals（CLCs） have recently sparked an enormous amount of interest in the development of soft matter materials due to their unique ability to self-organize into a helical supra-molecular architecture and their excellent selective reflection of light based on the Bragg relationship.Nowadays,by the virtue of building the self-organized nanostructures with pitch gradient or non-uniform pitch distribution,extensive work has already been performed to obtain CLC films with a broad reflection band.Based on authors＇ many years＇ research experience,this critical review systematically summarizes the physical and optical background of the CLCs with broadband reflection characteristics,methods to obtain broadband reflection of CLCs,as well as the application in the field of intelligent optical modulation materials.Combined with the research status and the advantages in the field,the important basic and applied scientific problems in the research direction are also introduced.

Localized Optical Waves in Defocusing Regime of Negative-Index Materials

We study optical localized waves on a plane-wave background in negative-index materials governed by the defocusing nonlinear Schr6dinger equation with self-steepening effect. Important characteristics of localized waves, such as the excitations, transitions, propagation stability, and mechanism, are revealed in detail. An intrigu- ing sequential transition that involves the rogue wave, antidark-dark soliton pair, antidark soliton and antidark soliton pair can be triggered as the self-steepening effect attenuates. The corresponding phase diagram is estab- lished in the defocusing regime of negative-index materials. The propagation stability of the localized waves is confirmed numerically. In particular, our results illuminate the transition mechanism by establishing the exact correspondence between the transition and the modulation instability analysis.

SYNTHESIS AND OPTICAL PROPERTIES OF POLY (THIENYLACETYLENES)

3-Ethynyl-4-(trimethylsilyl)thiophene (1a) and 3-ethynyl-4-bromothiophene (1b) selectively undergo acetylene polymerizations in the presence of the MoCl5- and WCl6-Ph3SiH catalysts to give soluble, high-molecular-weight poly(thienylacetylenes) (2) (M-w up to 602000) in high yields (up to 100%). Light transmission spectra of THF solutions of 2 continuously red-shift with increasing concentration. The concentratochromism shows a logarithmic concentration dependence; that is, the optical transitions of 2 are predictably tunable by simply changing their concentrations.

Effects of Nb2O5 on thermal stability and optical properties of Er^3＋-doped tellurite glasses

Er^3＋-doped tellurite glasses with molar compositions of xNb2O5 - （14.7 - x）Na2O-10ZnO-5K2O-10GeO260TeO2-0.3Er2O3 （x = 0, 3, 5, 7 and 9） have been investigated for developing 1.5 μm fibre and planar amplifiers. The effects of Nb2O5 on the thermal stability and optical properties of Er^3＋-doped tellurite glasses have been discussed. It is noted that the incorporation of Nb205 （x=5） increases the thermal stability of tellurite glasses significantly. Er^3＋-doped niobium tellurite glasses exhibit a large stimulated emission cross-section （7.2×10^-21 - 10.7×10^-21 cm^2） and the gain bandwidth, FWHM×σ^peak （274 ×10^-28 - 480×10^-28 cm^3）, which are significantly higher than that of silicate and phosphate glasses. In addition, the intensity of upconversion luminescence of the Er3＋-doped niobium tellurite glasses decreases rapidly with increasing Nb2O5 content. As a result, Er^3＋-doped niobium tellurite glasses might be a potential candidate for developing laser or optical amplifier devices.

Optical properties of titanium oxide films obtained by cathodic arc plasma deposition

Structural and optical properties of nanometric titanium oxide（TixOy） films obtained by cathodic arc plasma deposition were investigated. Phase analysis by x-ray diffraction and Fouriertransform infrared spectroscopy showed the presence of anatase, rutile, Ti_2O_3, Ti_4O_7 and amorphous phases. Scanning electron microscopy images showed well-developed surface morphology with nano-patterns. Spectroscopic ellipsometry revealed film thicknesses of 53 and50 nm, variable refractive indices dependent on the light wavelength and close to zero extinction coefficients for wavelengths higher than 500 nm. On the basis of ultraviolet–visible spectroscopy data and using the Tauc equation, band gap values for direct and indirect electron transitions were determined.

Synthesis and Nonlinear Optical Property of a Series of New Chromophores Containing Furan Ring as the Only Conjugation Bridge

This paper reports the synthesis and the nonlinear optical property of a series of new chromophores which contain furan ring as the only conjugation bridge for the first time. They are characterized by UV-VIS, FT-IR, 1H NMR, MS and elemental analysis. Their dipole moment and the first-order molecular hyperpolarizability (b) are calculated and compared with those of the analogues containing either benzene or thiophene as the conjugation bridge.

Optical Properties and Structural Perfection of Chicago Sky Blue 6B-doped KDP Crystals

KDP crystals doped with Chicago Sky Blue 6B（CSB-6B） were grown by traditional lowering temperature method.The optical properties and structural perfection of KDP crystals were investigated by transmittance spectra and high-resolution X-ray diffraction,respectively.The results indicate that CSB-6B tends to be incorporated into the pyramidal sector of KDP crystals（PyS-KDP） and lead to inclusions parallel to（101） face.Additionally,the transmittance of as-grown KDP crystals decreases as the amount of CSB-6B increases. Moreover,the rocking curves of PyS-KDP suggest that CSB-6B can deteriorate the structural perfection of PyS-KDP.

Linear and nonlinear optical analysis on semiorganic-proline cadmium chloride single crystal

In the current investigation,L-proline cadmium chloride monohydrate（LPCC） single crystal is grown by a slow solvent evaporation technique to identify its credibility for nonlinear optical device applications.The constituent elements of LPCC crystal are determined by the energy dispersive spectroscopic（EDS） technique.The single crystal x-ray diffraction technique is used to determine the structural dimensions of LPCC crystal.The UV-visible studies are carried out within a wavelength range of 200 nm–1100 nm to determine the optical transmittance of LPCC crystal.The linear optical parameters of LPCC crystal are evaluated using the transmittance data to discuss its importance for distinct optical devices.The Nd：YAG laser assisted Kurtz–Perry test is carried out to determine the enhancement in second harmonic generation efficiency of LPCC crystal with reference to KDP crystal.The Z-scan technique is employed to assess the third order nonlinear optical（TONLO） properties of LPCC crystal at 632.8 nm.The Z-scan data are utilized to evaluate the TONLO refraction,absorption and susceptibility of LPCC crystal.The color oriented luminescence behavior of LPCC crystal is investigated within a spectral range of 350 nm–700 nm.The dependence of dielectric constant and dielectric loss on temperature and frequency is evaluated through the dielectric measurement studies.

Extraordinary propagation characteristics of electromagnetic waves in one-dimensional anti-PT-symmetric ring optical waveguide network

In this paper, we design a one-dimensional anti-PT-symmetric ring optical waveguide network(1 D APTSPROWN).Using the three-material network equation and the generalized Floquet–Bloch theorem, we investigate its photonic mode distribution, and observe weak extremum spontaneous anti-PT-symmetric breaking points(WBPs) and strong extremum spontaneous anti-PT-symmetric breaking points(SBPs). Then the transmission spectrum is obtained by using the threematerial network equation and the generalized eigenfunction method. The 1 D APTSPROWN is found to generate ultrastrong transmission near SBPs and ultra-weak transmission near WBPs and SBPs, with the maximal and minimal transmissions being 4.08× 1012 and 7.08× 10-52, respectively. The maximal transmission has the same order of magnitude as the best-reported result. It is not only because the distribution of photonic modes generated by the 1 D APTSROWN results in the coupling resonance and anti-resonance, but also because the 1 D APTSROWN composed of materials whose real parts of refractive indices are positive and negative has two kinds of phase effects, which results in the resonance and antiresonance effects in the same kind of photonic modes. This demonstrates that the anti-PT-symmetric and PT-symmetric optical waveguide networks are quite different, which leads to a more in-depth understanding of anti-PT-symmetric and PT-symmetric structures. This work has the potential for paving a new approach to designing single photon emitters,optical amplifiers, and high-efficiency optical energy saver devices.

Optical nonlinearities of tetracarbonyl-chromium triphenyl phosphine complex

The new tetracarbonyl - chromium-triphenyl phosphine complex was synthesized and characterized using ultraviolet（UV）-visible,Fourier transform infrared（FTIR）,and nuclear magnetic resonance（NMR） techniques.The characterization results confirm the molecular structure of the new complex.The z-scan measurements were done by diode laser[continuous wave（CW）]to estimate the nonlinear optical parameter（X^3）.The results led to calculate three parameters：the groundstate cross sections（σ_g）,the excited-state cross sections（σ_（ex））,and thermo-optic coefficient of the new complex.This study indicated that our complex is a suitable for photonic applications.