First-Principle Study on the Electronic Structure and Optical Property of New Diluted Magnetic Semiconductor(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO

The band structure,DOSs,and optical properties of(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO,including dielectric function,absorption function,reflection function,and energy loss spectrum were studied by using the first-principles calculation.The calculation results indicate that(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO is a direct bandgap semiconductor with a bandgap of 1.1 eV.The Fermi surface is asymmetric and exhibits spin splitting phenomenon.The new type of dilute magnetic semiconductor(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO exhibits significant light loss around 70 eV,with light reflection gradually increasing after 30 eV,and light absorption mainly occurring around 8-30 eV.These results also provide a basis for the discovery of more types of 1111 phase new dilute magnetic semiconductors in the future.

Study on the optical property and biocompatibility of a tissue engineering cornea

AIM: To study the optical property and biocompatibility of a tissue engineering cornea. METHODS: The cross-linker of N- (3-Dimethylaminoropyl)-N'ethylcarbodiimide hydrochloride (EDC)/ N-Hydroxysuccinimide (NHS) was mixed with Type I collagen at 10% (weight/volume). The final solution was molded to the shape of a corneal contact lens. The collagen concentrations of 10%, 12.5%, 15%, 17.5% and 20% artificial corneas were tested by UV/vis-spectroscopy for their transparency compared with normal rat cornea. 10-0 sutures were knotted on the edges of substitute to measure the corneal buttons's mechanical properties. Normal rat corneal tissue primary culture on the collagen scaffold was observed in 4 weeks. Histopathologic examinations were performed after 4 weeks of in vitro culturing. RESULTS: The collagen scaffold appearance was similar to that of soft contact lens. With the increase of collagen concentration, the transparency of artificial corneal buttons was diminished, but the toughness of the scaffold was enhanced. The scaffold transparency in the 10% concentration collagen group resembled normal rat cornea. To knot and embed the scaffold under the microscope, 20% concentration collagen group was more effective during implantation than lower concentrations of collagen group. In the first 3 weeks, corneal cell proliferation was highly active. The shapes of cells that grew on the substitute had no significant difference when compared with the cells before they were moved to the scaffold. However, on the fortieth day, most cells detached from the scaffold and died. Histopathologic examination of the primary culture scaffold revealed well grown corneal cells tightly attached to the scaffold in the former culturing. CONCLUSION: Collagen scaffold can be molded to the shape of soft contact corneal lens with NHS/EDC. The biological stability and biocompatibility of collagen from animal species may be used as material in preparing to engineer artificial corneal scaffold.

Constraint Inversion Algorithm of Lidar Equationfor Deriving Aerosol Optical Property

A key question of the backward integration algorithm to lidar equation is how to determine the far-endboundary value. This paper develops a Constraint Inversion Algorithm (CIA) for deriving the value andthen the aerosol extinction profile from lidar signals, which uses the ground-level horizontal lidar signals asthe constraint information. The smaller the wavelength is, the more sensitive to the variation of aerosol extinction to backscatter ratio solved by CIA. According to the property an algorithm is further proposed tosimultaneously retrieve the aerosol extinction profile, the size distribution and the imaginary part of its reflective index from the multi-wavelength lidar observations. CIA is tested in the inversion simulations withsatisfactory result.

Facile Synthesis of SnO_2 Hollow Microspheres and Their Optical Property

SnO2 hollow microspheres were fabricated via a hydrothermal synthesis method assisting by the complex surfactant system of polyacrylamide and polyethylene glycol.Observation by field emission scanning electron microscopy （FESEM） showed the SnO2 hollow spheres were composed of nanoparticles.The growth mechanism for the formation of hollow spheres was proposed.UV spectroscopy and photoluminescence （PL） were used to investigate the optical properties of the products.The PL result showed that four peaks,containing the emission from recombination of free excitons,were observed in the photoluminescence spectrum.

On the Role of Bond Function in Nonlinear Optical Property Calculations for HF,HCI,LiH,H_(2)O and NH_(3)

Dond function basis sets have been used to calculate the molecular nonlinear optical properties which include hyperpolarizability βo , polarizability ao , and dipole moment μo for six molecules. The calculations at the fourth-order Moller-Plesset approximation (MP4) have recovered more than 90% of the experimental values βo , comparecl to that as low as 75% by the other authors. The calculated values of αo and iuo are also in good agreement with those of experiments and superior to that from other work. It is shown that the bond functions improve the calculated results at SCF level and especially at the level of the correction of electronic correlation (MP2 and MP4).

Electronic Absorption Spectra and Third-Order Nonlinear Optical Property of Dinaphtho[2,3-b:2’,3’-d]Thiophene-5,7,12,13- Tetraone (DNTTRA) and Its Phenyldiazenyl Derivatives: DFT Calculations

Third-order nonlinear optical (NLO) materials have broad application prospects in high-density data storage, optical computer, modern laser technology, and other high-tech industries. The structures and frequencies of Dinaphtho[2,3-b:2’,3’-d]thiophene-5,7,12,13-tetraone (DNTTRA) and its 36 derivatives containing azobenzene were calculated by using density functional theory B3LYP and M06-2X methods at 6-311++g(d, p) level, respectively. Besides, the atomic charges of natural bond orbitals (NBO) were analyzed. The frontier orbitals and electron absorption spectra of A-G5 molecule were calculated by TD-DFT (TD-B3LYP/6-311++g(d, p) and TD-M06-2X/6-311++g(d, p)). The NLO properties were calculated by effective finite field FF method and self-compiled program. The results show that 36 molecules of these six series are D-π-A-π-D structures. The third-order NLO coefficients γ (second-order hyperpolarizability) of the D series molecules are the largest among the six series, reaching 107 atomic units (10-33 esu) of order of magnitude, showing good third-order NLO properties. Last, the third-order NLO properties of the azobenzene ring can be improved by introducing strong electron donor groups (e.g. -N(CH3)2 or -NHCH3) in the azobenzene ring, so that the third-order NLO materials with good performance can be obtained.

Synthesis and Optical Property Study on ZnO Nanostructures Via Vapor Phase Growth

Nanostructural zinc oxide films have been synthesized via vapor phase growthby heating pure zinc powder. Scanning electron microscopy ( SEM) images and X-ray diffraction (XRD)results showed that four kinds of morphologies ZnO nanostructures namely nanowires, well-alignednanorods, nanofeathers and hexagonal nano-rods were formed and all of wurtzite structural crystals.The results indicated that the temperature and substrate play an important role in the formation ofdifferent morphologies of ZnO nanostructures. The photoluminescence (PL) measurement was carried outfor the well-aligned nanorods ZnO sample and blue emission peaks at 420 and 444 nm have beenobserved at room temperature. And the blue emission mechanism is discussed.

Synthesis of Poly[(3-octanoylpyrrole-2,5-diyl)-p-nitrobenzylidene] and Its Third-order Nonlinear Optical Property

A novel soluble π-conjugated polymer, poly[(3-octanoylpyrrole-2,5-diyl)-p-nitrobenzylidene] (POPNBE), was synthesized by a five-step reaction. As a result of introducing a long acyl to pyrrole at 3-position, the polymer can be easily solved in polar solvents and be processed into films. The chemical structures of the intermediates and POPNBE were characterized by FTIR, 1H NMR, and UV-Vis-NIR spectrometries. The absorption band in the range of 400-600 nm in the UV-Vis-NIR spectrum is due to the π-π * band gap transition. The optical band gap of POPNBE obtained from the optical absorption is about 1.72 eV. The resonant third-order nonlinear optical property of POPNBE at 532 nm was studied by using the degenerate four-wave mixing(DFWM) technique. The resonant third-order nonlinear optical susceptibility of POPNBE is about 3.42×10 -8 esu.

The Optical Property of CPD Prepared CdS Films

CdS films were prepared with chemical pyrolysis deposition (CPD) at 450℃ during film growth, and these CdS films were also annealed at different temperature from 200-500℃.The optical property of the CdS films before and after annealing was investigated at different measuring temperature from 10K to 300K. Optical absorption spectra show that the absorption edge is towards the shorter wavelengths, and the energy band gaps deduced from the plots of (α·hν) 2 vs. hν are increased when the measuring temperature is decreased. The optical behaviors of the CdS films annealed at a certain temperature seem to have the similar tendency at different measuring temperature. Based on dE- ex/dT curve dependent on annealing temperature, some phenomena related microstructure in CdS films could be found.

NONLINEAR OPTICAL PROPERTY OF para-DISUBSTITUTED BENZYLIDENE-ANILINE DERIVATIVES

Forty para-disubstituted benzylidene-aniline derivatives were synthesized,and their second harmonic generation(SHG)efficiency was measured by the Kurtz powder technique.The effect of the electronic property and the position of the substituents on powder SHG efficiency was studied.

Synthesis,Crystal and Electronic Structures,and Optical Property of the Chiral Y4InSbS9

The chiral sulfide Y4InSbS9 has been prepared from stoichiometric elements at 1223 K in an evacuated silica tube. It crystallizes in the chiral tetragonal space group P43212 with a = 9.8784（3）, c = 27.3106（16） A, V = 2665.04（19） A^3, Z = 8, Mr = 880.75, Dc = 4.390 g/cm^3, μ = 22.285 mm^–1, F（000） = 3200, the final R = 0.0302 and wR = 0.0669 for 2961 observed reflections with I 〉 2σ（I）. The structure features infinite helical chains of [In2Sb2S（11）^10–]∞ propagating along the c direction and they are separated by isolated Y^3＋ cations and S2– anions. UV/Vis diffuse reflectance spectroscopy study shows that its optical gap is around 1.94 eV. Density functional theory（DFT） study indicates an indirect band gap with an electronic transfer excitation of S 3p to Y 5d orbital electrons.

Crystal Structure and Third-order Nonlinear Optical Property Studies on Copper(Ⅱ) Complex Containing NS Donor Ligand

A novel Schiff base ligand (HL) derived from S-methyldithiocabazate and pmethoxylbenzaldehyde was prepared and characterized. The Schiff base ligand acts as a single negatively charged bidentate ligand fondng D-M-D type comPlex (D=donor, M=metal). Single crystal X-ray diffraction analysis of the copper(Ⅱ) complex established that the geometry around Cu (Ⅱ) is square-planar with two equivalent M-N and M-S bonds. The two phenyl rings and the coordinated plane are almost in one plane fotheng an electronic delocalization system. Their thirdorder response was also studied.

Phase Diagram, Growth and Optical Property of the LaBWO_6 Crystal

The phase diagram, growth and optical property of LaBWO6 crystal are reported. LaBWO6 crystal melts congruently at 1078 ℃. Based on the pseudo-ternary phase diagram of LaBWO6-（Li2WO4/LiF） -B203, the LaBWO6 crystals have been firstly grown by the flux method. LaBWO6 crystal crystallizes in the orthorhombic system, space group P222 with a = 4.1, b = 10.31 and c = 21.71 A. LaBWO6 Crystal exhibits high transparency in a range from 327 to 1100 nm. The absorption edge of the crystal in the UV range is at 293 nm. The SHG efficient of LaBWO6 crystal is 0.3 times as large as that of the KDP crystal.

Influence of Alumina Addition on the Optical Property of Zirconia/Alumina Composite Dental Ceramics

The influence of various alumina additions on the optical property of zirconia/alumina composite ceramics was investigated. The relative sintered densities, transmittances, color and the microstructure of the composite ceramics were studied. The experimental results showed that the relative sintered densities and transmittances decreased with alumina addition. The lightness increased obviously but the chroma change was small. Pure zirconia nanopowders sintered densely could obtain the relatively high transmittance, while the transmittance and the lightness of slight addition changed significantly. The zirconia/alumina composite ceramics with alumina addition less than 7.5wt% could achieve the relatively stable and reliable optical properties.

First‑principles study on electronic structure,optical and magnetic properties of rare earth elements X(X=Sc,Y,La,Ce,Eu)doped with two‑dimensional GaSe

The electronic structure,magnetic,and optical properties of two-dimensional(2D)GaSe doped with rare earth elements X(X=Sc,Y,La,Ce,Eu)were calculated using the first-principles plane wave method based on den-sity functional theory.The results show that intrinsic 2D GaSe is a p-type nonmagnetic semiconductor with an indi-rect bandgap of 2.6611 eV.The spin-up and spin-down channels of Sc-,Y-,and La-doped 2D GaSe are symmetric,they are non-magnetic semiconductors.The magnetic moments of Ce-and Eu-doped 2D GaSe are 0.908μ_(B)and 7.163μ_(B),which are magnetic semiconductors.Impurity energy levels appear in both spin-up and spin-down chan-nels of Eu-doped 2D GaSe,which enhances the probability of electron transition.Compared with intrinsic 2D GaSe,the static dielectric constant of the doped 2D GaSe increases,and the polarization ability is strengthened.The ab-sorption spectrum of the doped 2D GaSe shifts in the low-energy direction,and the red-shift phenomenon occurs,which extends the absorption spectral range.The optical reflection coefficient of the doped 2D GaSe is improved in the low energy region,and the improvement of Eu-doped 2D GaSe is the most obvious.

Optical Modeling of Sea Salt Aerosols Using in situ Measured Size Distributions and the Impact of Larger Size Particles

Sea salt aerosols play a critical role in regulating the global climate through their interactions with solar radiation.The size distribution of these particles is crucial in determining their bulk optical properties.In this study,we analyzed in situ measured size distributions of sea salt aerosols from four field campaigns and used multi-mode lognormal size distributions to fit the data.We employed super-spheroids and coated super-spheroids to account for the particles’non-sphericity,inhomogeneity,and hysteresis effect during the deliquescence and crystallization processes.To compute the singlescattering properties of sea salt aerosols,we used the state-of-the-art invariant imbedding T-matrix method,which allows us to obtain accurate optical properties for sea salt aerosols with a maximum volume-equivalent diameter of 12μm at a wavelength of 532 nm.Our results demonstrated that the particle models developed in this study were successful in replicating both the measured depolarization and lidar ratios at various relative humidity(RH)levels.Importantly,we observed that large-size particles with diameters larger than 4μm had a substantial impact on the optical properties of sea salt aerosols,which has not been accounted for in previous studies.Specifically,excluding particles with diameters larger than 4μm led to underestimating the scattering and backscattering coefficients by 27%−38%and 43%−60%,respectively,for the ACE-Asia field campaign.Additionally,the depolarization ratios were underestimated by 0.15 within the 50%−70%RH range.These findings emphasize the necessity of considering large particle sizes for optical modeling of sea salt aerosols.

Optical Properties of GaAs/AlGaAs Nanowires Grown on Pre-etched Si Substrates

GaAs-based nanomaterials are essential for near-infrared nano-photoelectronic devices due to their exceptional optoelectronic properties.However,as the dimensions of GaAs materials decrease,the development of GaAs nanowires(NWs)is hindered by type-Ⅱquantum well structures arising from the mixture of zinc blende(ZB)and wurtzite(WZ)phases and surface defects due to the large surface-to-volume ratio.Achieving GaAs-based NWs with high emission efficiency has become a key research focus.In this study,pre-etched silicon substrates were combined with GaAs/AlGaAs core-shell heterostructure to achieve GaAs-based NWs with good perpendicularity,excellent crystal structures,and high emission efficiency by leveraging the shadowing effect and surface passivation.The primary evidence for this includes the prominent free-exciton emission in the variable-temperature spectra and the low thermal activation energy indicated by the variable-power spectra.The findings of this study suggest that the growth method described herein can be employed to enhance the crystal structure and optical properties of otherⅢ-Ⅴlow-dimensional materials,potentially paving the way for future NW devices.

Fabrication of amorphous nanoporous ZrO_(2)/SiO_(2) aerogel enabling nonlinear optical properties

Amorphous oxides have unique physicochemical properties with extensive opto-electronic applications such as the thin-film transistor,light-emitting diode backplanes,and supercontinuum generation.In this contribution,we synthesize the amorphous ZrO_(2)/SiO_(2) nanoporous aerogel with high structural integrity.With the femtosecond excitation laser at 800–1,064 nm,the broadband second harmonic generation is observed.The nonlinear optical properties of the as-prepared ZrO_(2)/SiO_(2) aerogel are investigated at 1.0μm and 1.5μm for the first time.Subsequently,the amorphous ZrO_(2)/SiO_(2) saturable absorber is originally applied in the Yb-doped and Er-doped fiber lasers to realize the mode-locking operations.In the Yb-doped fiber laser,the dissipative soliton resonance mode-locking operation is demonstrated with the largest pulse duration of 22 ns at a repetition rate of 7.8 MHz and a high signal-to-noise ratio of 64 dB.In the Er-doped fiber laser,a conventional soliton mod-locking regime is observed with an ultrashort pulse width of 960 fs,a repetition frequency of 6.55 MHz,and a time-bandwidth production of 0.347.Our work shows the good ability of the ZrO_(2)/SiO_(2) aerogel in generating ultrafast pulses and extends the saturable absorber into the amorphous material realm.

Structure,electronic,and nonlinear optical properties of superalkaline M_(3)O(M=Li,Na)doped cyclo[18]carbon

Cyclo[18]carbon has received considerable attention thanks to its novel geometric configuration and special electronic structure.Superalkalis have low ionization energy.Doping a superalkali in cyclo[18]carbon is an effective method to improve the optical properties of the system because considerable electron transfer occurs.In this paper,the geometry,bonding properties,electronic structure,absorption spectrum,and nonlinear optical(NLO)properties of superalkaline M_(3)O(M=Li,Na)-doped cyclo[18]carbon were studied by using density functional theory.M_(3)O and the C_(18) rings are not coplanar.The C_(18) ring still exhibits alternating long and short bonds.The charge transfer between M_(3)O and C_(18) forms stable[M_(3)O]+[C_(18)]-ionic complexes.C_(18)M_(3)O(M=Li,Na)shows striking optical nonlinearity,i.e.,their first-and second-order hyperpolarizability(βvec andγ||)increase considerably atλ=1907 nm and 1460 nm.

The Effect of Uncaria gambir on Optical Properties and Thermal Stability of CNF/PVA Biocomposite Films

Cellulose-based film has gained popularity as an alternative to synthetic polymers due to its outstanding properties.Among all types of cellulose materials available,cellulose nanofiber(CNF)has great potential to be utilized in a diverse range of applications,including as a film material.In this study,CNF biocomposite film was prepared by using polyvinyl alcohol(PVA)as a matrix and Uncaria gambir extract as a filler.This study aims to investigate the effect of Uncaria gambir extract on the optical properties and thermal stability of the produced film.The formation of the CNF biocomposite films was confirmed using Fourier Transform Infrared Spectroscopy,their transmittance characteristics were measured using UV-Vis spectroscopy and a transmittance meter,while their reflectance was determined using a reflectance meter.The results revealed that the addition of Uncaria gambir extract to the CNF biocomposite film improved its UV-shielding properties,as indicated by the lower percentage of transmittance in the visible region,10%–70%.In addition,its reflectance increased to 10.6%compared to the CNF film without the addition of Uncaria gambir extract.Furthermore,the thermal stability of the CNF biocomposite film with the addition of Uncaria gambir extract improved to around 400℃–500℃.In conclusion,the results showed that CNF biocomposite film prepared by adding Uncaria gambir extract can be a promising candidate for optical and thermal management materials.