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.
To rationalize the design of D-π-A type organic small-molecule nonlinear optical materials,a theory guided machine learning framework is constructed.Such an approach is based on the recognition that the optical prope...To rationalize the design of D-π-A type organic small-molecule nonlinear optical materials,a theory guided machine learning framework is constructed.Such an approach is based on the recognition that the optical property of the molecule is predictable upon accumulating the contribution of each component,which is in line with the concept of group contribution method in thermodynamics.To realize this,a Lewis-mode group contribution method(LGC)has been developed in this work,which is combined with the multistage Bayesian neural network and the evolutionary algorithm to constitute an interactive framework(LGC-msBNN-EA).Thus,different optical properties of molecules are afforded accurately and efficientlyby using only a small data set for training.Moreover,by employing the EA model designed specifically for LGC,structural search is well achievable.The origins of the satisfying performance of the framework are discussed in detail.Considering that such a framework combines chemical principles and data-driven tools,most likely,it will be proven to be rational and efficient to complete mission regarding structure design in related fields.展开更多
A new organic/inorganic hybrid nonlinear optical (NLO) material was developed by the sol-gel process of an alkoxysilane dye with tetraethoxysilane. A NLO moiety based on 4-nitro-4 ' -hydroxy azobenzene was covalen...A new organic/inorganic hybrid nonlinear optical (NLO) material was developed by the sol-gel process of an alkoxysilane dye with tetraethoxysilane. A NLO moiety based on 4-nitro-4 ' -hydroxy azobenzene was covalently bonded to the triethoxysilane derivative, i.e, gamma -isocyanatopropyl triethoxysilane. The preparation process and properties of the sol-gel derived NLO polymer were studied and characterized by SEM, FTIR,H-1-NMR, UV-Vis, DSC and second harmonic generation (SHG) measurement. The results indicated that the chemical bonding of the chromophores to the inorganic SiO2 networks induces low dipole alignment relaxation and preferable orientational stability. The SHG measurements also showed that the bonded polymer film containing 75 wt% of the akoxysilane dye has a high electro-optic coefficient (r(33)) of 7.1 pm/V at 1.1 mum wavelength, and exhibit good SHG stability, the r(33) values can maintain about 92.7% of its initial value at room temperature for 90 days, and can maintain about 59.3% at 100 degreesC for 300 min.展开更多
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, ...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, H-1 NMR, MS and elemental analysis. Their dipole moment and the first-order molecular hyperpolarizability (beta) are calculated and compared with those or the analogues containing either benzene or thiophene as file conjugation bridge.展开更多
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 con...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.展开更多
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 ch...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.展开更多
Based on graphene, a new class of second-order nonlinear optical(NLO) material, the lithium salt of NH2-substituted graphene nanoribbon with the twofold donor(D)/acceptor(A) mode, was reported. Eight stable 2Li-...Based on graphene, a new class of second-order nonlinear optical(NLO) material, the lithium salt of NH2-substituted graphene nanoribbon with the twofold donor(D)/acceptor(A) mode, was reported. Eight stable 2Li-2NH2-GNR lithium salts, especially cis lithium salts, display considerably large β0 values. The combination of NH2-substituting and cis Li-doping makes β0 greatly increased from 0(GNR) to 1.2×105―2.9×105 a.u.(cis-2Li- 2NH2-GNRs). Our largest β0 value(2.9×105 a.u.) for cis-2Li-1,3-2NH2-AGNR is comparable to the record value of 1.7×105 a.u. for a long donor-acceptor polyene.展开更多
It is challenging to cooperatively improve the nonlinear optical(NLO)efficiency and the laser-induced damage threshold(LIDT).This work reports a novel IR NLO materials CsInP_(2)S_(7)(CIPS)designed by combination the s...It is challenging to cooperatively improve the nonlinear optical(NLO)efficiency and the laser-induced damage threshold(LIDT).This work reports a novel IR NLO materials CsInP_(2)S_(7)(CIPS)designed by combination the strategies of alkali metals substitution and microscopic NLO units PS4 introduction based on AgGaS_(2).CIPS was composed of strongly distorted[InS_(6)]^(9-)octahedra and[P_(2)S_(7)]4-dimers constructed by corner-sharing[PS_(4)]^(3-),which increase the NLO efficiency and decrease thermal expansion anisotropy simultaneously.Compared with AgGaS_(2),CIPS exhibited strong phase matchable NLO response ca.1.1×AGS@2.1μm,high LIDT ca.20.8×AgGaS_(2),and IR transparency up to 15.3μm.Structural analysis and theoretical investigation confirmed that large SHG effect and ultrahigh LIDT of CIPS originated from the synergistic contribution of[InS_(6)]^(9-)octahedra and[P_(2)S_(7)]4-dimers.These results indicate that CIPS is a promising NLO candidate in the mid-IR region,and this study provides a new approach for developing potential NLO-LIDT compatible materials.展开更多
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 ...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.展开更多
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 contradicti...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.展开更多
Due to the remarkable carrier mobility and nonlinear characteristic, MoS2 is considered to be a powerful competitor as an effective optical modulated material in fiber lasers. In this paper, the MoS2 films are prepare...Due to the remarkable carrier mobility and nonlinear characteristic, MoS2 is considered to be a powerful competitor as an effective optical modulated material in fiber lasers. In this paper, the MoS2 films are prepared by the chemical vapor deposition method to guarantee the high quality of the crystal lattice and uniform thickness. The transfer of the films to microfiber and the operation of gold plated films ensure there is no heat-resistant damage and anti-oxidation. The modulation depth of the prepared integrated microfiber-MoS2 saturable absorber is 11.07%. When the microfiber-MoS2 saturable absorber is used as a light modulator in the Q-switching fiber laser, the stable pulse train with a pulse duration of 888 ns at 1530.9 nm is obtained. The ultimate output power and pulse energy of output pulses are 18.8 mW and 88 nJ, respectively. The signal-to-noise ratio up to 60 dB indicates the good stability of the laser. This work demonstrates that the MoS2 saturable absorber prepared by the chemical vapor deposition method can serve as an effective nonlinear control device for the Q-switching fiber laser.展开更多
Q-switched lasers have occupied important roles in industrial applications such as laser marking,engraving,welding,and cutting due to their advantages in high pulse energy.Here,SnS_(2)-based Q-switched lasers are impl...Q-switched lasers have occupied important roles in industrial applications such as laser marking,engraving,welding,and cutting due to their advantages in high pulse energy.Here,SnS_(2)-based Q-switched lasers are implemented.Consid-ering that SnS_(2) inherits the thickness sensitive optical characteristics of TMD,three kinds of SnS2 with different thick-ness are characterized in terms of nonlinearity and used to realize the Q-switched pulses under consistent implementa-tion conditions for comparison tests.According to the results,the influence of thickness variation on the nonlinear per-formance of saturable absorber,such as modulation depth and absorption intensity,and the influence on the correspond-ing laser are analyzed.In addition,compared with other traditional saturable absorbers,the advantage of SnS_(2) in realiz-ing ultrashort pulses is also noticed.Our work explores the thickness-dependent nonlinear optical properties of SnS_(2),and the rules found is of great reference value for the establishment of target lasers.展开更多
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 P...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.展开更多
In spite of decades of great efforts,it is still very challenging to realize accurate design and synthesis of second-order nonlinear optical(NLO)crystals.KBe_(2)BO_(3)F_(2)(KBBF)is the sole NLO material that can outpu...In spite of decades of great efforts,it is still very challenging to realize accurate design and synthesis of second-order nonlinear optical(NLO)crystals.KBe_(2)BO_(3)F_(2)(KBBF)is the sole NLO material that can output deep-ultraviolet light by direct second-harmonic generation process,so it is an ideal choice to use KBBF as the structural template to design environment-friendly candidates with better growth habit based on the reported compounds.In this review,we will elaborate the accurate design and synthesis of high-performance NLO ma-terials from the perspective of microscopic crystal structure based on KBBF,hoping to provide deep understanding on how to rationally design and synthesize targeted compounds efficiently and quickly.In addition,according to multiple requirements on ultraviolet NLO crystals,including second-harmonic generation,cut-off edge,and birefringence,we propose a new concept so-called quality factor to comprehensively evaluate the overall per-formance of new ultraviolet NLO materials.This concept would help to directly and readily evaluate the ability of an ultraviolet NLO material to achieve practical NLO output.展开更多
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 appli...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.展开更多
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 disp...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.展开更多
Ca 4YO(BO 3) 3(YCOB) which possesses good NLO properties and chemical stability,is an excellent candidate for frequency conversion crystals to produce green and blue light (SHG and THG of Nd∶YAG laser).In this paper,...Ca 4YO(BO 3) 3(YCOB) which possesses good NLO properties and chemical stability,is an excellent candidate for frequency conversion crystals to produce green and blue light (SHG and THG of Nd∶YAG laser).In this paper,preparation of the feed material and the vertical Bridgman growth condition for YCOB crystal is reported for the first time to our knowledge. YCOB crystals have been grown from the feed materials composed of Y 2O 3(4N),CaCO 3/CaO (A.R.) and H 3BO 3/B 2O 3(4N)by vertical Bridgman method.Since Ca 4YO(BO 3) 3 melts congruently,the feed material should be prepared in the stoichiometric composition.The evaporation of B 2O 3 at high temperature and the hygroscopicity of CaO,B 2O 3 and Y 2O 3 were carefully considered.It was showed by experiments that the feed material prepared by directly and thoroughly mixing together stoichiometric amount of Y 2O 3,CaO and B 2O 3 is suitable for the Bridgman growth of YCOB crystal.The melting point of YCOB crystal is 1510℃,and Pt crucible less than 1.0mm thick was chosen.The temperature of the furnace was controlled from 1560℃ to 1650℃.Owing to the extremely high melting points of both Y 2O 3 and CaO,the feed material had been heated at the above temperature for more than 10 hours before growth so that it melts thoroughly.The growth rate of 0.2-0.6mm/h and the temperature gradient near the solid-liquid interface of 40-60°C/cm were chosen.The Crack free and transparent YCOB crystals with 25mm in diameter and 50mm long have been grown in near sealed Pt crucibles under the above growth condition,which suggests that the vertical Bridgman method is suitable for the growth of YCOB crystal.展开更多
A transmission-type tungsten disulfide(WS_2)-based saturable absorber(SA) is fabricated and applied to passively Q-switched Nd:YVO_4 laser.The WS_2 nanosheets are deposited on a quartz substrate by the vertical e...A transmission-type tungsten disulfide(WS_2)-based saturable absorber(SA) is fabricated and applied to passively Q-switched Nd:YVO_4 laser.The WS_2 nanosheets are deposited on a quartz substrate by the vertical evaporation method.By inserting the WS2 SA into the plano-concave laser cavity,we achieve 153-ns pulses with an average output power of1.19 W at 1064 nm.To the best of our knowledge,both of them are the best results among those obtained by the Q-switched solid-state lasers with WS_2-based absorbers.The repetition rate ranges from 1.176 MHz to 1.578 MHz.As far as we know,it is the first time that MHz level Q-switched pulses have been generated in all solid state lasers based on low-dimensional materials so far.展开更多
A new zinc(II) complex, Zn(2-NH2py)2Br2 (py=pyridine), has been synthesized, and its molecular structure has been confirmed by IR, elemental analysis and -ray crystal structure analysis. Its space group is P21/n with...A new zinc(II) complex, Zn(2-NH2py)2Br2 (py=pyridine), has been synthesized, and its molecular structure has been confirmed by IR, elemental analysis and -ray crystal structure analysis. Its space group is P21/n with Mr=413.43 (C10H12Br2N4Zn), a=7.435(2), b=12.865(3), c=14.186(4)? b=94.08(2)? V=1353.5(5) 3, Z=4, Dc=2.029 g/cm3, F(000)=328, ?2.378mm-1, R=0.0283, wR=0.0501. The total observed reflections with I≥2?I) were 5314, of which the independent reflections were 3106. The complex structure contains a distorted tetrahedron formed by four atoms coordinated to zinc atom, namely two bromide atoms and two nitrogen atoms. The two ZnBr bond lengths within one molecule, 2.3763(6) and 2.4002(5)? respectively, are not equal; and so are the two ZnN bond lengths, which are 2.031(2) and 2.044(2)?respectively. The calculation results using PM3 method through MOPAC software package in Chem 3D show that its first molecular hyperpolarizability b value is 5.210-30esu, which is comparable with that of p-nitroaniline. No bulk SHG effect has been detected due to the centrosymmetric space group.展开更多
The growth of heterogeneous crystal has aroused a great deal of interest in recent years. In this study, KH2PO4 (KDP)/KTaO3 (KT) heterogeneous crystal is acquired based on the KT substrate. Here, we report the obs...The growth of heterogeneous crystal has aroused a great deal of interest in recent years. In this study, KH2PO4 (KDP)/KTaO3 (KT) heterogeneous crystal is acquired based on the KT substrate. Here, we report the observation of the oriented layer-by-layer structure in KDP/KT composite crystal by scanning electron microscopy (SEM). The structure of KDP/KT composite crystal is accurately identified by transmission electron microscopy (TEM) for the first time and we find that the KT crystals dope into KDP crystal in the growth process with the mode of doping. It can be obtained from the analysis of crystal structure that the structure difference leads to the doping growth mode. Our research demonstrates a facile method to fabricate a composite nonlinear optical crystal based on KDP/KT heterostructure, and might shed light on potential applications of the composite nonlinear optical crystal.展开更多
文摘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.
基金support by the Key Research and Development Program of Zhejiang Province(2023C01102,2023C01208,2022C01208)。
文摘To rationalize the design of D-π-A type organic small-molecule nonlinear optical materials,a theory guided machine learning framework is constructed.Such an approach is based on the recognition that the optical property of the molecule is predictable upon accumulating the contribution of each component,which is in line with the concept of group contribution method in thermodynamics.To realize this,a Lewis-mode group contribution method(LGC)has been developed in this work,which is combined with the multistage Bayesian neural network and the evolutionary algorithm to constitute an interactive framework(LGC-msBNN-EA).Thus,different optical properties of molecules are afforded accurately and efficientlyby using only a small data set for training.Moreover,by employing the EA model designed specifically for LGC,structural search is well achievable.The origins of the satisfying performance of the framework are discussed in detail.Considering that such a framework combines chemical principles and data-driven tools,most likely,it will be proven to be rational and efficient to complete mission regarding structure design in related fields.
基金This work was supported by the Postdoctoral Science Foundation of Guangdong Province (No. 9644) and the Natural Science Fund of Guangdong Province(No. 990629).
文摘A new organic/inorganic hybrid nonlinear optical (NLO) material was developed by the sol-gel process of an alkoxysilane dye with tetraethoxysilane. A NLO moiety based on 4-nitro-4 ' -hydroxy azobenzene was covalently bonded to the triethoxysilane derivative, i.e, gamma -isocyanatopropyl triethoxysilane. The preparation process and properties of the sol-gel derived NLO polymer were studied and characterized by SEM, FTIR,H-1-NMR, UV-Vis, DSC and second harmonic generation (SHG) measurement. The results indicated that the chemical bonding of the chromophores to the inorganic SiO2 networks induces low dipole alignment relaxation and preferable orientational stability. The SHG measurements also showed that the bonded polymer film containing 75 wt% of the akoxysilane dye has a high electro-optic coefficient (r(33)) of 7.1 pm/V at 1.1 mum wavelength, and exhibit good SHG stability, the r(33) values can maintain about 92.7% of its initial value at room temperature for 90 days, and can maintain about 59.3% at 100 degreesC for 300 min.
基金the National Natural Science Foundation of China(No.29774018) a grant from the National Key Fundamental Research Program of China.
文摘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, H-1 NMR, MS and elemental analysis. Their dipole moment and the first-order molecular hyperpolarizability (beta) are calculated and compared with those or the analogues containing either benzene or thiophene as file conjugation bridge.
基金UGC,New Delhi,India for awarding Maulana Azad National Fellowship(Grant No.F1-17.1/2015-16/MANF-2015-17-MAH-68193)RCAMSKing Khalid University,Saudi Arabia for support
文摘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.
文摘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.
基金Supported by the National Natural Science Foundation of China(Nos.20773046, 20773048 and 21073075)
文摘Based on graphene, a new class of second-order nonlinear optical(NLO) material, the lithium salt of NH2-substituted graphene nanoribbon with the twofold donor(D)/acceptor(A) mode, was reported. Eight stable 2Li-2NH2-GNR lithium salts, especially cis lithium salts, display considerably large β0 values. The combination of NH2-substituting and cis Li-doping makes β0 greatly increased from 0(GNR) to 1.2×105―2.9×105 a.u.(cis-2Li- 2NH2-GNRs). Our largest β0 value(2.9×105 a.u.) for cis-2Li-1,3-2NH2-AGNR is comparable to the record value of 1.7×105 a.u. for a long donor-acceptor polyene.
基金the Natural Science Foundation of China(No.22105218).
文摘It is challenging to cooperatively improve the nonlinear optical(NLO)efficiency and the laser-induced damage threshold(LIDT).This work reports a novel IR NLO materials CsInP_(2)S_(7)(CIPS)designed by combination the strategies of alkali metals substitution and microscopic NLO units PS4 introduction based on AgGaS_(2).CIPS was composed of strongly distorted[InS_(6)]^(9-)octahedra and[P_(2)S_(7)]4-dimers constructed by corner-sharing[PS_(4)]^(3-),which increase the NLO efficiency and decrease thermal expansion anisotropy simultaneously.Compared with AgGaS_(2),CIPS exhibited strong phase matchable NLO response ca.1.1×AGS@2.1μm,high LIDT ca.20.8×AgGaS_(2),and IR transparency up to 15.3μm.Structural analysis and theoretical investigation confirmed that large SHG effect and ultrahigh LIDT of CIPS originated from the synergistic contribution of[InS_(6)]^(9-)octahedra and[P_(2)S_(7)]4-dimers.These results indicate that CIPS is a promising NLO candidate in the mid-IR region,and this study provides a new approach for developing potential NLO-LIDT compatible materials.
基金supported by the National Natural Science Foundation of China,China(Grant Nos.22071179,51902224,51972230,52172006,51890864,51890865)Natural Science Foundation of Tianjin,China(Grant Nos.20JCJQJC00060,21JCJQJC00090).
文摘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.
基金supported by the National Natural Science Foundation of China(21921001,22075283,92161125,U21A20508)the Youth Innovation Promotion Association of Chinese Academy of Sciences of China(2021300)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2020ZZ108,2021ZR205).
文摘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.
基金Project supported by the National Natural Science Foundation of China(Grant No.11674036)the Beijing Youth Top-notch Talent Support Program,China(Grant No.2017000026833ZK08)the Fund of State Key Laboratory of Information Photonics and Optical Communications,Beijing University of Posts and Telecommunications,China(Grant Nos.IPOC2016ZT04 and IPOC2017ZZ05)
文摘Due to the remarkable carrier mobility and nonlinear characteristic, MoS2 is considered to be a powerful competitor as an effective optical modulated material in fiber lasers. In this paper, the MoS2 films are prepared by the chemical vapor deposition method to guarantee the high quality of the crystal lattice and uniform thickness. The transfer of the films to microfiber and the operation of gold plated films ensure there is no heat-resistant damage and anti-oxidation. The modulation depth of the prepared integrated microfiber-MoS2 saturable absorber is 11.07%. When the microfiber-MoS2 saturable absorber is used as a light modulator in the Q-switching fiber laser, the stable pulse train with a pulse duration of 888 ns at 1530.9 nm is obtained. The ultimate output power and pulse energy of output pulses are 18.8 mW and 88 nJ, respectively. The signal-to-noise ratio up to 60 dB indicates the good stability of the laser. This work demonstrates that the MoS2 saturable absorber prepared by the chemical vapor deposition method can serve as an effective nonlinear control device for the Q-switching fiber laser.
基金the financial support from the National Natural Science Foundation of China(11875008,12075034)Open Research Fund of State Key Laboratory of Pulsed Power Laser Technology(Grant SKL2019KF04)Fundamental Research Funds for the Central Universities(2019XD-A09-3).
文摘Q-switched lasers have occupied important roles in industrial applications such as laser marking,engraving,welding,and cutting due to their advantages in high pulse energy.Here,SnS_(2)-based Q-switched lasers are implemented.Consid-ering that SnS_(2) inherits the thickness sensitive optical characteristics of TMD,three kinds of SnS2 with different thick-ness are characterized in terms of nonlinearity and used to realize the Q-switched pulses under consistent implementa-tion conditions for comparison tests.According to the results,the influence of thickness variation on the nonlinear per-formance of saturable absorber,such as modulation depth and absorption intensity,and the influence on the correspond-ing laser are analyzed.In addition,compared with other traditional saturable absorbers,the advantage of SnS_(2) in realiz-ing ultrashort pulses is also noticed.Our work explores the thickness-dependent nonlinear optical properties of SnS_(2),and the rules found is of great reference value for the establishment of target lasers.
文摘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.
基金the National Natural Science Foundation of China(Grant No.22122507,22193042,21833010,61975207,and 21921001)the Natural Science Foundation of Fujian Province(Grant No.2022J02012)+2 种基金the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No,Y202069)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant No.ZDBS-LY-SLH024)Fujian Institute of Innovation(Grant No.FJCXY18010201)in Chinese Academy of Sciences.
文摘In spite of decades of great efforts,it is still very challenging to realize accurate design and synthesis of second-order nonlinear optical(NLO)crystals.KBe_(2)BO_(3)F_(2)(KBBF)is the sole NLO material that can output deep-ultraviolet light by direct second-harmonic generation process,so it is an ideal choice to use KBBF as the structural template to design environment-friendly candidates with better growth habit based on the reported compounds.In this review,we will elaborate the accurate design and synthesis of high-performance NLO ma-terials from the perspective of microscopic crystal structure based on KBBF,hoping to provide deep understanding on how to rationally design and synthesize targeted compounds efficiently and quickly.In addition,according to multiple requirements on ultraviolet NLO crystals,including second-harmonic generation,cut-off edge,and birefringence,we propose a new concept so-called quality factor to comprehensively evaluate the overall per-formance of new ultraviolet NLO materials.This concept would help to directly and readily evaluate the ability of an ultraviolet NLO material to achieve practical NLO output.
基金Supported by National Natural Science Foundation of China(21971171,21875146)。
文摘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.
基金financial support from the Guangdong Innovative Research Team Program of China (201101C0105067115)DSTA Singapore (Project DSTA-NUS-DIRP/9010100347)National Research Foundation Singapore (R398-001-062-281)
文摘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.
文摘Ca 4YO(BO 3) 3(YCOB) which possesses good NLO properties and chemical stability,is an excellent candidate for frequency conversion crystals to produce green and blue light (SHG and THG of Nd∶YAG laser).In this paper,preparation of the feed material and the vertical Bridgman growth condition for YCOB crystal is reported for the first time to our knowledge. YCOB crystals have been grown from the feed materials composed of Y 2O 3(4N),CaCO 3/CaO (A.R.) and H 3BO 3/B 2O 3(4N)by vertical Bridgman method.Since Ca 4YO(BO 3) 3 melts congruently,the feed material should be prepared in the stoichiometric composition.The evaporation of B 2O 3 at high temperature and the hygroscopicity of CaO,B 2O 3 and Y 2O 3 were carefully considered.It was showed by experiments that the feed material prepared by directly and thoroughly mixing together stoichiometric amount of Y 2O 3,CaO and B 2O 3 is suitable for the Bridgman growth of YCOB crystal.The melting point of YCOB crystal is 1510℃,and Pt crucible less than 1.0mm thick was chosen.The temperature of the furnace was controlled from 1560℃ to 1650℃.Owing to the extremely high melting points of both Y 2O 3 and CaO,the feed material had been heated at the above temperature for more than 10 hours before growth so that it melts thoroughly.The growth rate of 0.2-0.6mm/h and the temperature gradient near the solid-liquid interface of 40-60°C/cm were chosen.The Crack free and transparent YCOB crystals with 25mm in diameter and 50mm long have been grown in near sealed Pt crucibles under the above growth condition,which suggests that the vertical Bridgman method is suitable for the growth of YCOB crystal.
基金Project supported by the National Natural Science Foundation of China(Grant No.61378024)
文摘A transmission-type tungsten disulfide(WS_2)-based saturable absorber(SA) is fabricated and applied to passively Q-switched Nd:YVO_4 laser.The WS_2 nanosheets are deposited on a quartz substrate by the vertical evaporation method.By inserting the WS2 SA into the plano-concave laser cavity,we achieve 153-ns pulses with an average output power of1.19 W at 1064 nm.To the best of our knowledge,both of them are the best results among those obtained by the Q-switched solid-state lasers with WS_2-based absorbers.The repetition rate ranges from 1.176 MHz to 1.578 MHz.As far as we know,it is the first time that MHz level Q-switched pulses have been generated in all solid state lasers based on low-dimensional materials so far.
基金This work was financed by the National Key Fundamental Research Program of China.
文摘A new zinc(II) complex, Zn(2-NH2py)2Br2 (py=pyridine), has been synthesized, and its molecular structure has been confirmed by IR, elemental analysis and -ray crystal structure analysis. Its space group is P21/n with Mr=413.43 (C10H12Br2N4Zn), a=7.435(2), b=12.865(3), c=14.186(4)? b=94.08(2)? V=1353.5(5) 3, Z=4, Dc=2.029 g/cm3, F(000)=328, ?2.378mm-1, R=0.0283, wR=0.0501. The total observed reflections with I≥2?I) were 5314, of which the independent reflections were 3106. The complex structure contains a distorted tetrahedron formed by four atoms coordinated to zinc atom, namely two bromide atoms and two nitrogen atoms. The two ZnBr bond lengths within one molecule, 2.3763(6) and 2.4002(5)? respectively, are not equal; and so are the two ZnN bond lengths, which are 2.031(2) and 2.044(2)?respectively. The calculation results using PM3 method through MOPAC software package in Chem 3D show that its first molecular hyperpolarizability b value is 5.210-30esu, which is comparable with that of p-nitroaniline. No bulk SHG effect has been detected due to the centrosymmetric space group.
基金supported by the National Natural Science Foundation of China–Chinese Academy of Engineering Physics Academic Fund(NSFC-NSAF)(Grant No.U1330118)the National Natural Science Foundation of China(Grant No.51402053)the Shanghai Education Development Foundation,China(Grant No.09SG01)
文摘The growth of heterogeneous crystal has aroused a great deal of interest in recent years. In this study, KH2PO4 (KDP)/KTaO3 (KT) heterogeneous crystal is acquired based on the KT substrate. Here, we report the observation of the oriented layer-by-layer structure in KDP/KT composite crystal by scanning electron microscopy (SEM). The structure of KDP/KT composite crystal is accurately identified by transmission electron microscopy (TEM) for the first time and we find that the KT crystals dope into KDP crystal in the growth process with the mode of doping. It can be obtained from the analysis of crystal structure that the structure difference leads to the doping growth mode. Our research demonstrates a facile method to fabricate a composite nonlinear optical crystal based on KDP/KT heterostructure, and might shed light on potential applications of the composite nonlinear optical crystal.