Achieving non-centrosymmetric(NCS) configurations in ABX3-type hybrid halides remains a critical challenge for nonlinear optical(NLO) materials due to the conflicting requirements of high second-harmonic generation(SH...Achieving non-centrosymmetric(NCS) configurations in ABX3-type hybrid halides remains a critical challenge for nonlinear optical(NLO) materials due to the conflicting requirements of high second-harmonic generation(SHG) response,wide bandgap,and phase-matching capabilities.Herein,we propose a triplesite modulation strategy by synergistically tailoring the A-site cations(2-methylimidazole cation/1-ethyl-3-methylimidazole cation),B-site metals(Sn^(2+)/Pb^(2+)),and X-site halogens(Cl/Br),which effectively disrupts lattice symmetry and enables NCS crystallization.Our results demonstrate a strong SHG response,an expanded optical bandgap and increased birefringence.The optimized compound C_(6)H_(11)N_(2)PbCl_(3) exhibits a moderately strong SHG efficiency of 3.8 × KDP,a wide bandgap(3.87 eV),and enhanced birefringence(0.139@1064 nm),surpassing majority hybrid NLO materials.The innovative anionic framework introduced here broadens the scope of hybrid NLO crystals,facilitating the integration of various aromatic heterocyclic cations.This research provides a robust strategic framework for the development of advanced NLO materials.展开更多
In this paper,a double-effect DNN-based Digital Back-Propagation(DBP)scheme is proposed and studied to achieve the Integrated Communication and Sensing(ICS)ability,which can not only realize nonlinear damage mitigatio...In this paper,a double-effect DNN-based Digital Back-Propagation(DBP)scheme is proposed and studied to achieve the Integrated Communication and Sensing(ICS)ability,which can not only realize nonlinear damage mitigation but also monitor the optical power and dispersion profile over multi-span links.The link status information can be extracted by the characteristics of the learned optical fiber parameters without any other measuring instruments.The efficiency and feasibility of this method have been investigated in different fiber link conditions,including various launch power,transmission distance,and the location and the amount of the abnormal losses.A good monitoring performance can be obtained while the launch optical power is 2 dBm which does not affect the normal operation of the optical communication system and the step size of DBP is 20 km which can provide a better distance resolution.This scheme successfully detects the location of single or multiple optical attenuators in long-distance multi-span fiber links,including different abnormal losses of 2 dB,4 dB,and 6 dB in 360 km and serval combinations of abnormal losses of(1 dB,5 dB),(3 dB,3 dB),(5 dB,1 dB)in 360 km and 760 km.Meanwhile,the transfer relationship of the estimated coefficient values with different step sizes is further investigated to reduce the complexity of the fiber nonlinear damage compensation.These results provide an attractive approach for precisely sensing the optical fiber link status information and making correct strategies timely to ensure optical communication system operations.展开更多
Herein,we report the synthesis and third-order nonlinear optical(NLO)properties of a novel cage-based 2D metal-organic framework constructed from Ti_(4)L_(6)(L4-=embonate)cage combined with Mg^(2+)and tris[4-(1H-imida...Herein,we report the synthesis and third-order nonlinear optical(NLO)properties of a novel cage-based 2D metal-organic framework constructed from Ti_(4)L_(6)(L4-=embonate)cage combined with Mg^(2+)and tris[4-(1H-imidazol-1-yl)phenyl]amine(tipa)ligand,whose molecular formula is(Me_(2)CH_(2))_(2)[Mg_(3)(Ti_(4)L_(6))(tipa)(H_(2)O)_(12)](PTC‑378).The Ti_(4)L_(6)tetrahedral cages serve as robust building units,while the Mg^(2+)ions and tipa ligands provide structural stability and tunable optical properties.The resulting PTC‑378 film exhibited intriguing third-order NLO property,which was systematically investigated using Z-scan techniques.Our results demonstrate that the synergistic interaction between Ti_(4)L_(6)cages andπ-conjugated ligands significantly enhances the NLO performance of the materials.CCDC:2453909.展开更多
The generation of optical vortices from nonlinear photonic crystals(NPCs)with spatially modulated second-order nonlinearity offers a promising approach to extend the working wavelength and topological charge of vortex...The generation of optical vortices from nonlinear photonic crystals(NPCs)with spatially modulated second-order nonlinearity offers a promising approach to extend the working wavelength and topological charge of vortex beams for various applications.In this work,the second harmonic(SH)optical vortex beams generated from nonlinear fork gratings under Gaussian beam illumination are numerically investigated.The far-field intensity and phase distributions,as well as the orbital angular momentum(OAM)spectra of the SH beams,are analyzed for different structural topological charges and diffraction orders.Results reveal that higher-order diffraction and larger structural topological charges lead to angular interference patterns and non-uniform intensity distributions,deviating from the standard vortex profile.To optimize the SH vortex quality,the effects of the fundamental wave beam waist,crystal thickness,and grating duty cycle are explored.It is shown that increasing the beam waist can effectively suppress diffraction order interference and improve the beam’s quality.This study provides theoretical guidance for enhancing the performance of nonlinear optical devices based on NPCs.展开更多
It remains highly challenging to achieve the high-order nonlinear optical(NLO)properties of atomically precise metal nanoclusters via template-maintained manipulation.Here,based on the M_(1)Ag_(24)(SR)_(18)(M=Ag/Au/Pt...It remains highly challenging to achieve the high-order nonlinear optical(NLO)properties of atomically precise metal nanoclusters via template-maintained manipulation.Here,based on the M_(1)Ag_(24)(SR)_(18)(M=Ag/Au/Pt/Pd;SR=2,4-dimethylthiophenol)cluster template,we demonstrated that the innermost kernel alloying rendered these nanoclusters highly controllable towards the nonlinear optics.The Pd-alloyed Pd_(1)Ag_(24)(SR)_(18) only dis-played single-photon-excited fluorescence,while the homo-silver Ag_(25)(SR)_(18) nanocluster generated the two-photonexcited fluorescence characterization.The Au-and Pt-doped M_(1)Ag_(24)(SR)_(18) nanoclusters showed high-order three-and four-photon-excited fluorescence,respectively,demonstrating that the order-by-order control over the nonlinear optics of nanoclusters has been accomplished.Moreover,Pd_(1)Ag_(24)(SR)_(18) with high-order NLO characterization exhibited the best optical limiting performance under 1000 nm excitation,in agreement with its most prominent NLO property.Overall,this work presents an intriguing cluster template that enables successive order control over the nonlinear optics of atomically precise metal nanoclusters,hopefully paving the way for developing cluster-based nanomaterials with customized optical characterizations.展开更多
Short-wavelength nonlinear optical(NLO)crystals can convert a specific wavelength of light to ultraviolet(UV)and deep-UV region.To date,most of the commercialized UV and deep-UV NLO materials are borate crystals.By co...Short-wavelength nonlinear optical(NLO)crystals can convert a specific wavelength of light to ultraviolet(UV)and deep-UV region.To date,most of the commercialized UV and deep-UV NLO materials are borate crystals.By combining the merits of borates and silicates,borosilicates exhibit some unique advantages of rich structural types,moderate second harmonic generation(SHG)response,and high UV transmittance.This paper summarizes the known NLO borosilicates which can be grouped into two types according to the linkage modes of BO and SiO units:(1)borosilicates with BOSi covalent bond,and(2)borosilicates with isolated BO and SiO units.The structural features,SHG intensities,and UV cutoff edges of these borosilicates are discussed.Finally,future perspectives in this field are presented.展开更多
Sulfates are always promising short-wave ultraviolet(UV)nonlinear optical(NLO)candidates,if their birefringence could be greatly improved.Here,in terms of the insufficient birefringence,the unity of heteroleptic tetra...Sulfates are always promising short-wave ultraviolet(UV)nonlinear optical(NLO)candidates,if their birefringence could be greatly improved.Here,in terms of the insufficient birefringence,the unity of heteroleptic tetrahedral groups and triangular ones was proposed and implemented.Thus,a new semiorganic crystal,[C(NH_(2))_(3)]S_(3)O_(6)(G_(2)S_(3)O_(6)),was obtained,which is composed of[S_(3)O_(6)]^(2-)and[C(NH_(2))_(3)]+groups.It exhibits excellent optical properties with a short absorption cutoff edge of 218 nm,a strong NLO response of 1.4×KH_(2)PO_(4),and more especially,a large birefringence of 0.097@546 nm.This birefringence leap makes the G_(2)S_(3)O_(6) crystal achieve a phase-matching behavior under a 532 nm laser.Thus,the synergy of[S_(3)O_(6)]^(2-)and[C(NH_(2))_(3)]~+groups results in excellent optical performances.This finding opens a new horizon for exploring novel UV NLO crystals.展开更多
In this paper,the third-order nonlinear optical(NLO)properties of covalent organic framework(COF)materials with conjugated amphoteric ion structure are studied for the first time.A highly ordered crystalline ultrathin...In this paper,the third-order nonlinear optical(NLO)properties of covalent organic framework(COF)materials with conjugated amphoteric ion structure are studied for the first time.A highly ordered crystalline ultrathin films of the ionic COF material PySQ-iCOF was successfully fabricated using a solid-liquid interface method,meanwhile the building units extracted to be independent small molecule,1-PySA,were synthesized for comparative studies.Compared to 1-PySA,PySQ-iCOF possesses not only a larger conjugated system but also exhibits enhanced polarization and charge transfer capabilities.The NLO properties of PySQ-iCOF and the small molecule 1-PySA were investigated using Z-scan technique at a wavelength of 532 nm,revealing the PySQ-iCOF thin film exhibits outstanding NLO performance.Specifically,it demonstrates saturable absorption under nanosecond(ns)pulse laser irradiation(β=9.59×10^(-6) m/W),while exhibiting reverse saturable absorption under femtosecond(fs)pulse conditions(β=6.91×10^(-8) m/W).Furthermore,the PySQ-iCOF film exhibits strong negative refractive nonlinearity,−6×10^(-12) m^(2)/W for ns and -3.8×10^(-13) m^(2)/W for fs,respectively.Transient absorption spectroscopy studies indicate that the pulse-width-dependent nonlinear absorption char-acteristics of the PySQ-iCOF film originate from the generation of triplet excited states.Both nonlinear absorption coefficient and nonlinear refractive index of the PySQ-iCOF film surpass those of most reported organic materials measured under comparable conditions,which provides huge potential in all-optical manipulating and switching at the nanoscale as outstanding NLO materials.展开更多
This paper investigates the third-order nonlinear optical properties of two azo-nickel chelate compounds by the optical Kerr gate method at 830 nm wavelength with pulse duration of 120 fs. Both of the two compounds ex...This paper investigates the third-order nonlinear optical properties of two azo-nickel chelate compounds by the optical Kerr gate method at 830 nm wavelength with pulse duration of 120 fs. Both of the two compounds exhibited large third-order optical nonlinearity. The second-order hyperpolarizability,γ, of Compound 1 is of 1.0 × 10^-31 esu. Due to the charge transfer, the γ of Compound 2 with electron donor and acceptor group is 4.9 × 10^-31 esu, which is a four-time enhancement in comparison with Compound i. The absorption spectra show that the electron push-pull effect, which induces intramolecular charge transfer, leads to the increased optical nonlinearity.展开更多
The interactions of charge transfer(CT)and nonradiative energy transfer(ET)in heterojunctions of two-dimensional(2D)transition metal dichalcogenides and quasi-2D single crystal perovskite thin films have the potential...The interactions of charge transfer(CT)and nonradiative energy transfer(ET)in heterojunctions of two-dimensional(2D)transition metal dichalcogenides and quasi-2D single crystal perovskite thin films have the potential applications in sensor,energy harvesting and solar cells.However,the CT and ET between them are not clear.Herein,we examine the ET in a(PEA)_(2)PbI_(4)/WS_(2)(PEA stands for phenethylamine and(PEA)_(2)PbI_(4)is abbreviated as PEPI)heterojunction using combined ultrafast spectroscopy and nonlinear optical absorption measurements.The ET from PEPI to WS_(2)predicted by band alignment is first observed with photoluminescence spectroscopy and then revealed by femtosecond transient absorption spectroscopy to exhibit a high ET efficiency approximating 68%.展开更多
Diamond-like AgGaS_(2)(DL AGS),as the typical infrared nonlinear optical(IR NLO)material,has suffered from its intrinsic drawbacks like narrow band gap(E_(g))and low laser-induced damage threshold(LIDT).In this work,b...Diamond-like AgGaS_(2)(DL AGS),as the typical infrared nonlinear optical(IR NLO)material,has suffered from its intrinsic drawbacks like narrow band gap(E_(g))and low laser-induced damage threshold(LIDT).In this work,by first introducing[NaS_(8)]polyhedral unit into the A_(2)^(Ⅰ)Q^(Ⅵ)-Ag_(2)Q^(Ⅵ)-C_(2)^(Ⅲ)Q_(3)^(Ⅵ) system,a new Ag-based sulfide NaAg_(3)Ga_(8)S_(14) with diamond-like framework(DLF)has been successfully synthesized via a high-temperature solid-state method in experiment.The compound shows a wide Eg(~3.0 eV),high LIDT(3.0×AGS)and moderate phase-matching NLO response(~0.7×AGS),effectively balancing the E_(g)(≥3.0 eV)and NLO response(≥0.5×AGS),demonstrating its promise for IR NLO applications.Theoretical calculations elucidate the orbital hybridization between Na 3s,Ag 4d5s and S 3p enhances E_(g),and the aligned NLO-active units([AgS_(4)]and[GaS_(4)])induce moderate NLO response in the compound.These findings not only expand the chemical and structural diversities of Ag-based chalcogenides,but also provide effective strategies for designing DLF functional materials derived from diamond-like structures.展开更多
We propose a novel all-optical sampling method using nonlinear polarization rotation in a semiconductor optical amplifier. A rate-equation model capable of describing the all-optical sampling mechanism is presented in...We propose a novel all-optical sampling method using nonlinear polarization rotation in a semiconductor optical amplifier. A rate-equation model capable of describing the all-optical sampling mechanism is presented in this paper. Based on this model, we investigate the optimized operating parameters of the proposed system by simulating the output intensity of the probe light as functions of the input polarization angle, the phase induced by the polarization controller, and the ori- entation of the polarization beam splitter. The simulated results show that we can obtain a good linear slope and a large linear dynamic range,which is suitable for all-optical sampling. The operating power of the pump light can be less than lmW. The presented all-optical sampling method can potentially operate at a sampling rate up to hundreds GS/s and needs low optical power.展开更多
Microstructure of GaAs/SiO 2 nanogranular thin films fabricated by radio frequency magnetron co sputtering technique and postannealing are investigated via atomic force microscope,X ray diffraction,and Rutherford b...Microstructure of GaAs/SiO 2 nanogranular thin films fabricated by radio frequency magnetron co sputtering technique and postannealing are investigated via atomic force microscope,X ray diffraction,and Rutherford backscattering spectroscopy.The results show that GaAs nanocrystals with average diameters from 1 5nm to 3 2nm (depending on the annealing temperature) are uniformly dispersed in the SiO 2 matrices.GaAs and SiO 2 are found in normal stoichiometry in the films.The nonlinear optical refraction and nonlinear optical absorption are studied by Z scan technique using a single Gaussian beam of pulse laser.The third order nonlinear optical refractive index and nonlinear absorption coefficient are enhanced due to the quantum confinement effects and estimated to be 4×10 -12 m 2/W and 2×10 -5 m/W respectively in nonresonant condition,while 2×10 -11 m 2/W and -1×10 -4 m/W respectively in quasi resonant condition.展开更多
A series of novel thermotropic liquid crystalline polyesters bearing nonlinear optical azobenzene side group were synthesized by high temperature solution polycondensation and their structures,thermal stability, phas...A series of novel thermotropic liquid crystalline polyesters bearing nonlinear optical azobenzene side group were synthesized by high temperature solution polycondensation and their structures,thermal stability, phase transition behavior and crystallinity were characterized by IR,elemental analysis, TG-DTA, polarizing optical microscope (POM) equipped with a hot stage and X-ray diffraction techniques. The results demonstrate that all the synthesized polyesters exhibit nematic liquid crystalline phases and show relatively high glass transition temperatures and good thermal stability.展开更多
Dendrimers are considered as a promising family of organic second-order nonlinear optical （NLO） polymers because of their well-defined structures, easily modified peripheral functional groups, interior branches and ...Dendrimers are considered as a promising family of organic second-order nonlinear optical （NLO） polymers because of their well-defined structures, easily modified peripheral functional groups, interior branches and central cores. In order to obtain NLO materials with high performance, dendrimer structures have been optimized in the past years, such as the ＂branch only＂ and the ＂root containing＂ type dendrimers. This feature article highlights the achievements in exploring the rational design of dendrimers, partially marked by their macroscopic NLO performance.展开更多
GaAs nanocrystals were prepared via a simple mechanical ball milling technique. The prepared GaAs nanocrystals have high purity and could form colloidal ethanol suspension without any surfactant additives. The colloid...GaAs nanocrystals were prepared via a simple mechanical ball milling technique. The prepared GaAs nanocrystals have high purity and could form colloidal ethanol suspension without any surfactant additives. The colloidal GaAs nanocrystal suspension displayed excellent two-photon absorption property over the visible and near-infrared region from 490 nm to 1064 nm, which enables it to become a promising broadband optical limiting material.展开更多
This paper demonstrates an all-optical switching model system comprising a single pulsed pump beam at 355 nm and a CW He-Ne signal beam at 632.8 nm with 2-（2＇-hydroxyphenyl）benzothiazole （HBT） in ethanol solution...This paper demonstrates an all-optical switching model system comprising a single pulsed pump beam at 355 nm and a CW He-Ne signal beam at 632.8 nm with 2-（2＇-hydroxyphenyl）benzothiazole （HBT） in ethanol solution. The origins of the optical switching effect were discussed. By the study of nonlinear optical properties for HBT in ethanol solvent, this paper verified that the excited-state intramolecular proton transfer （ESIPT） effect of HBT and the thermal effect of solvent worked on quite different time scales and together induced the change of the refractive index of HBT solution, leading to the signal beam deflection. The results indicated that the HBT molecule could be an excellent candidate for high-speed and high-sensitive optical switching devices.展开更多
A novel tolane 4-methoxy-4'-nitro-diphenyl-acetylene (MONA) has been prepared quantitatively by reacting cuprous p-methoxy phenyl-acetylene with p-iodonitrobenzene. A single crystal of the Moan was grown by soluti...A novel tolane 4-methoxy-4'-nitro-diphenyl-acetylene (MONA) has been prepared quantitatively by reacting cuprous p-methoxy phenyl-acetylene with p-iodonitrobenzene. A single crystal of the Moan was grown by solution growth method. The crystal was then characterized by X-ray diffraction structure analysis and second-harmonic generation(SHG)investigation. Polymorphous crystal forms of the MONA were grown from different solvents having different nonlinear optical properties depending on their different crystal structures. The relationship between the crystal growth and crystal structure is discusse.展开更多
Synthesis of the third-order nonlinear materials: bis (1,4-dihydroxynaphthalene) tetrathiafulvalene and bis (1,4-dialkoxylnaphthalene) tetrathiafulvalene has been achieved in four steps, starting from 2,3-dichloro-1,4...Synthesis of the third-order nonlinear materials: bis (1,4-dihydroxynaphthalene) tetrathiafulvalene and bis (1,4-dialkoxylnaphthalene) tetrathiafulvalene has been achieved in four steps, starting from 2,3-dichloro-1,4-naphthaquinone. The materials exhibit larger third-order nonlinear optical susceptibilities c(3) .展开更多
Nonlinear optical(NLO)crystals can be employed to expand the laser frequency and thus are of technical importance in advanced laser science.Noncentrosymmetric rare earth compounds keep attracting broad interest as a s...Nonlinear optical(NLO)crystals can be employed to expand the laser frequency and thus are of technical importance in advanced laser science.Noncentrosymmetric rare earth compounds keep attracting broad interest as a significant branch of NLO materials because the highly distorted structural motifs centered by rare earth ions could remarkably benefit the second harmonic generation.In this review,we proceed from structure-properties relationship and reveal the role of rare earth element in the optical properties of NLO materials.We believe that this work can deepen the understanding of rare earth-based NLO materials and provide some enlightenment for exploring novel practical NLO crystals.展开更多
基金supported by the National Natural Science Foundation of China (No.22275052)Department of Science and Technology of Hubei Province (Nos.2025AFA111 and 2024CSA076)。
文摘Achieving non-centrosymmetric(NCS) configurations in ABX3-type hybrid halides remains a critical challenge for nonlinear optical(NLO) materials due to the conflicting requirements of high second-harmonic generation(SHG) response,wide bandgap,and phase-matching capabilities.Herein,we propose a triplesite modulation strategy by synergistically tailoring the A-site cations(2-methylimidazole cation/1-ethyl-3-methylimidazole cation),B-site metals(Sn^(2+)/Pb^(2+)),and X-site halogens(Cl/Br),which effectively disrupts lattice symmetry and enables NCS crystallization.Our results demonstrate a strong SHG response,an expanded optical bandgap and increased birefringence.The optimized compound C_(6)H_(11)N_(2)PbCl_(3) exhibits a moderately strong SHG efficiency of 3.8 × KDP,a wide bandgap(3.87 eV),and enhanced birefringence(0.139@1064 nm),surpassing majority hybrid NLO materials.The innovative anionic framework introduced here broadens the scope of hybrid NLO crystals,facilitating the integration of various aromatic heterocyclic cations.This research provides a robust strategic framework for the development of advanced NLO materials.
基金supported by the National Key Research and Development Program of China (2019YFB1803905)the National Natural Science Foundation of China (No.62171022)+2 种基金Beijing Natural Science Foundation (4222009)Guangdong Basic and Applied Basic Research Foundation (2021B1515120057)the Scientific and Technological Innovation Foundation of Shunde Graduate School,USTB (No.BK19AF005)。
文摘In this paper,a double-effect DNN-based Digital Back-Propagation(DBP)scheme is proposed and studied to achieve the Integrated Communication and Sensing(ICS)ability,which can not only realize nonlinear damage mitigation but also monitor the optical power and dispersion profile over multi-span links.The link status information can be extracted by the characteristics of the learned optical fiber parameters without any other measuring instruments.The efficiency and feasibility of this method have been investigated in different fiber link conditions,including various launch power,transmission distance,and the location and the amount of the abnormal losses.A good monitoring performance can be obtained while the launch optical power is 2 dBm which does not affect the normal operation of the optical communication system and the step size of DBP is 20 km which can provide a better distance resolution.This scheme successfully detects the location of single or multiple optical attenuators in long-distance multi-span fiber links,including different abnormal losses of 2 dB,4 dB,and 6 dB in 360 km and serval combinations of abnormal losses of(1 dB,5 dB),(3 dB,3 dB),(5 dB,1 dB)in 360 km and 760 km.Meanwhile,the transfer relationship of the estimated coefficient values with different step sizes is further investigated to reduce the complexity of the fiber nonlinear damage compensation.These results provide an attractive approach for precisely sensing the optical fiber link status information and making correct strategies timely to ensure optical communication system operations.
文摘Herein,we report the synthesis and third-order nonlinear optical(NLO)properties of a novel cage-based 2D metal-organic framework constructed from Ti_(4)L_(6)(L4-=embonate)cage combined with Mg^(2+)and tris[4-(1H-imidazol-1-yl)phenyl]amine(tipa)ligand,whose molecular formula is(Me_(2)CH_(2))_(2)[Mg_(3)(Ti_(4)L_(6))(tipa)(H_(2)O)_(12)](PTC‑378).The Ti_(4)L_(6)tetrahedral cages serve as robust building units,while the Mg^(2+)ions and tipa ligands provide structural stability and tunable optical properties.The resulting PTC‑378 film exhibited intriguing third-order NLO property,which was systematically investigated using Z-scan techniques.Our results demonstrate that the synergistic interaction between Ti_(4)L_(6)cages andπ-conjugated ligands significantly enhances the NLO performance of the materials.CCDC:2453909.
基金supported by the National Nat-ural Science Foundation of China(Nos.12192251,12174185,92163216,and 62288101).
文摘The generation of optical vortices from nonlinear photonic crystals(NPCs)with spatially modulated second-order nonlinearity offers a promising approach to extend the working wavelength and topological charge of vortex beams for various applications.In this work,the second harmonic(SH)optical vortex beams generated from nonlinear fork gratings under Gaussian beam illumination are numerically investigated.The far-field intensity and phase distributions,as well as the orbital angular momentum(OAM)spectra of the SH beams,are analyzed for different structural topological charges and diffraction orders.Results reveal that higher-order diffraction and larger structural topological charges lead to angular interference patterns and non-uniform intensity distributions,deviating from the standard vortex profile.To optimize the SH vortex quality,the effects of the fundamental wave beam waist,crystal thickness,and grating duty cycle are explored.It is shown that increasing the beam waist can effectively suppress diffraction order interference and improve the beam’s quality.This study provides theoretical guidance for enhancing the performance of nonlinear optical devices based on NPCs.
基金the NSFC(U24A20480,22371003,22471001,22475002)the Ministry of Education,Natural Science Foundation of Anhui Province(2408085Y006)the Scientific Research Program of Universities in Anhui Province(2022AH030009).
文摘It remains highly challenging to achieve the high-order nonlinear optical(NLO)properties of atomically precise metal nanoclusters via template-maintained manipulation.Here,based on the M_(1)Ag_(24)(SR)_(18)(M=Ag/Au/Pt/Pd;SR=2,4-dimethylthiophenol)cluster template,we demonstrated that the innermost kernel alloying rendered these nanoclusters highly controllable towards the nonlinear optics.The Pd-alloyed Pd_(1)Ag_(24)(SR)_(18) only dis-played single-photon-excited fluorescence,while the homo-silver Ag_(25)(SR)_(18) nanocluster generated the two-photonexcited fluorescence characterization.The Au-and Pt-doped M_(1)Ag_(24)(SR)_(18) nanoclusters showed high-order three-and four-photon-excited fluorescence,respectively,demonstrating that the order-by-order control over the nonlinear optics of nanoclusters has been accomplished.Moreover,Pd_(1)Ag_(24)(SR)_(18) with high-order NLO characterization exhibited the best optical limiting performance under 1000 nm excitation,in agreement with its most prominent NLO property.Overall,this work presents an intriguing cluster template that enables successive order control over the nonlinear optics of atomically precise metal nanoclusters,hopefully paving the way for developing cluster-based nanomaterials with customized optical characterizations.
基金supported by the National Natural Science Foundation of China(No.21975224).
文摘Short-wavelength nonlinear optical(NLO)crystals can convert a specific wavelength of light to ultraviolet(UV)and deep-UV region.To date,most of the commercialized UV and deep-UV NLO materials are borate crystals.By combining the merits of borates and silicates,borosilicates exhibit some unique advantages of rich structural types,moderate second harmonic generation(SHG)response,and high UV transmittance.This paper summarizes the known NLO borosilicates which can be grouped into two types according to the linkage modes of BO and SiO units:(1)borosilicates with BOSi covalent bond,and(2)borosilicates with isolated BO and SiO units.The structural features,SHG intensities,and UV cutoff edges of these borosilicates are discussed.Finally,future perspectives in this field are presented.
基金supported by the National Natural Science Foundation of China(Nos.52172009 and 12275274)the Science and Technology Project of Fujian Province(Nos.2021J01519 and 2021H0043)the Instrument Developing Project of Chinese Academy of Sciences(No.YJKYYQ20210033)。
文摘Sulfates are always promising short-wave ultraviolet(UV)nonlinear optical(NLO)candidates,if their birefringence could be greatly improved.Here,in terms of the insufficient birefringence,the unity of heteroleptic tetrahedral groups and triangular ones was proposed and implemented.Thus,a new semiorganic crystal,[C(NH_(2))_(3)]S_(3)O_(6)(G_(2)S_(3)O_(6)),was obtained,which is composed of[S_(3)O_(6)]^(2-)and[C(NH_(2))_(3)]+groups.It exhibits excellent optical properties with a short absorption cutoff edge of 218 nm,a strong NLO response of 1.4×KH_(2)PO_(4),and more especially,a large birefringence of 0.097@546 nm.This birefringence leap makes the G_(2)S_(3)O_(6) crystal achieve a phase-matching behavior under a 532 nm laser.Thus,the synergy of[S_(3)O_(6)]^(2-)and[C(NH_(2))_(3)]~+groups results in excellent optical performances.This finding opens a new horizon for exploring novel UV NLO crystals.
基金the National Natural Science Foundation of China(22171076)Jing Li at the Technical Institute of Physics and Chemistry,Chinese Academy of Sciences(CAS),for his measurement of dynamic processes.
文摘In this paper,the third-order nonlinear optical(NLO)properties of covalent organic framework(COF)materials with conjugated amphoteric ion structure are studied for the first time.A highly ordered crystalline ultrathin films of the ionic COF material PySQ-iCOF was successfully fabricated using a solid-liquid interface method,meanwhile the building units extracted to be independent small molecule,1-PySA,were synthesized for comparative studies.Compared to 1-PySA,PySQ-iCOF possesses not only a larger conjugated system but also exhibits enhanced polarization and charge transfer capabilities.The NLO properties of PySQ-iCOF and the small molecule 1-PySA were investigated using Z-scan technique at a wavelength of 532 nm,revealing the PySQ-iCOF thin film exhibits outstanding NLO performance.Specifically,it demonstrates saturable absorption under nanosecond(ns)pulse laser irradiation(β=9.59×10^(-6) m/W),while exhibiting reverse saturable absorption under femtosecond(fs)pulse conditions(β=6.91×10^(-8) m/W).Furthermore,the PySQ-iCOF film exhibits strong negative refractive nonlinearity,−6×10^(-12) m^(2)/W for ns and -3.8×10^(-13) m^(2)/W for fs,respectively.Transient absorption spectroscopy studies indicate that the pulse-width-dependent nonlinear absorption char-acteristics of the PySQ-iCOF film originate from the generation of triplet excited states.Both nonlinear absorption coefficient and nonlinear refractive index of the PySQ-iCOF film surpass those of most reported organic materials measured under comparable conditions,which provides huge potential in all-optical manipulating and switching at the nanoscale as outstanding NLO materials.
基金supported by the National Key Basic Research Special Foundation (NKBRSF) of China (Grant No TG1999075207)the National Natural Science Foundation of China (Grant Nos 10434020,10521002,60378012,90206003,10328407 and 90101027)
文摘This paper investigates the third-order nonlinear optical properties of two azo-nickel chelate compounds by the optical Kerr gate method at 830 nm wavelength with pulse duration of 120 fs. Both of the two compounds exhibited large third-order optical nonlinearity. The second-order hyperpolarizability,γ, of Compound 1 is of 1.0 × 10^-31 esu. Due to the charge transfer, the γ of Compound 2 with electron donor and acceptor group is 4.9 × 10^-31 esu, which is a four-time enhancement in comparison with Compound i. The absorption spectra show that the electron push-pull effect, which induces intramolecular charge transfer, leads to the increased optical nonlinearity.
基金financially supported by the National Natural Science Foundation of China(Nos.52472153,11704081,and 62175210)Guangxi Natural Science Foundation(No.2020GXNSFAA297182)the special fund for"Guangxi Bagui Scholars,"National Science and Technology Innovation Talent Cultivation Program(No.2023BZRC016)
文摘The interactions of charge transfer(CT)and nonradiative energy transfer(ET)in heterojunctions of two-dimensional(2D)transition metal dichalcogenides and quasi-2D single crystal perovskite thin films have the potential applications in sensor,energy harvesting and solar cells.However,the CT and ET between them are not clear.Herein,we examine the ET in a(PEA)_(2)PbI_(4)/WS_(2)(PEA stands for phenethylamine and(PEA)_(2)PbI_(4)is abbreviated as PEPI)heterojunction using combined ultrafast spectroscopy and nonlinear optical absorption measurements.The ET from PEPI to WS_(2)predicted by band alignment is first observed with photoluminescence spectroscopy and then revealed by femtosecond transient absorption spectroscopy to exhibit a high ET efficiency approximating 68%.
基金supported by the Tianshan Talent Training Program(2024TSYCLJ0035)the Natural Science Foundation of the Xinjiang Uygur Autonomous Region(2024D01E30,2025D01B157)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0880000)the Open Fund of the Anhui Key Laboratory of Photonic Materials and Devices(AHKL2024KF02)the National Natural Sci-ence Foundation of China(22475234,52402017)the support from Tianchi Doctor Plan of Xinjiang Uygur Autonomous Region.
文摘Diamond-like AgGaS_(2)(DL AGS),as the typical infrared nonlinear optical(IR NLO)material,has suffered from its intrinsic drawbacks like narrow band gap(E_(g))and low laser-induced damage threshold(LIDT).In this work,by first introducing[NaS_(8)]polyhedral unit into the A_(2)^(Ⅰ)Q^(Ⅵ)-Ag_(2)Q^(Ⅵ)-C_(2)^(Ⅲ)Q_(3)^(Ⅵ) system,a new Ag-based sulfide NaAg_(3)Ga_(8)S_(14) with diamond-like framework(DLF)has been successfully synthesized via a high-temperature solid-state method in experiment.The compound shows a wide Eg(~3.0 eV),high LIDT(3.0×AGS)and moderate phase-matching NLO response(~0.7×AGS),effectively balancing the E_(g)(≥3.0 eV)and NLO response(≥0.5×AGS),demonstrating its promise for IR NLO applications.Theoretical calculations elucidate the orbital hybridization between Na 3s,Ag 4d5s and S 3p enhances E_(g),and the aligned NLO-active units([AgS_(4)]and[GaS_(4)])induce moderate NLO response in the compound.These findings not only expand the chemical and structural diversities of Ag-based chalcogenides,but also provide effective strategies for designing DLF functional materials derived from diamond-like structures.
文摘We propose a novel all-optical sampling method using nonlinear polarization rotation in a semiconductor optical amplifier. A rate-equation model capable of describing the all-optical sampling mechanism is presented in this paper. Based on this model, we investigate the optimized operating parameters of the proposed system by simulating the output intensity of the probe light as functions of the input polarization angle, the phase induced by the polarization controller, and the ori- entation of the polarization beam splitter. The simulated results show that we can obtain a good linear slope and a large linear dynamic range,which is suitable for all-optical sampling. The operating power of the pump light can be less than lmW. The presented all-optical sampling method can potentially operate at a sampling rate up to hundreds GS/s and needs low optical power.
文摘Microstructure of GaAs/SiO 2 nanogranular thin films fabricated by radio frequency magnetron co sputtering technique and postannealing are investigated via atomic force microscope,X ray diffraction,and Rutherford backscattering spectroscopy.The results show that GaAs nanocrystals with average diameters from 1 5nm to 3 2nm (depending on the annealing temperature) are uniformly dispersed in the SiO 2 matrices.GaAs and SiO 2 are found in normal stoichiometry in the films.The nonlinear optical refraction and nonlinear optical absorption are studied by Z scan technique using a single Gaussian beam of pulse laser.The third order nonlinear optical refractive index and nonlinear absorption coefficient are enhanced due to the quantum confinement effects and estimated to be 4×10 -12 m 2/W and 2×10 -5 m/W respectively in nonresonant condition,while 2×10 -11 m 2/W and -1×10 -4 m/W respectively in quasi resonant condition.
文摘A series of novel thermotropic liquid crystalline polyesters bearing nonlinear optical azobenzene side group were synthesized by high temperature solution polycondensation and their structures,thermal stability, phase transition behavior and crystallinity were characterized by IR,elemental analysis, TG-DTA, polarizing optical microscope (POM) equipped with a hot stage and X-ray diffraction techniques. The results demonstrate that all the synthesized polyesters exhibit nematic liquid crystalline phases and show relatively high glass transition temperatures and good thermal stability.
基金supported by the National Natural Science Foundation of China(No.21325416)
文摘Dendrimers are considered as a promising family of organic second-order nonlinear optical （NLO） polymers because of their well-defined structures, easily modified peripheral functional groups, interior branches and central cores. In order to obtain NLO materials with high performance, dendrimer structures have been optimized in the past years, such as the ＂branch only＂ and the ＂root containing＂ type dendrimers. This feature article highlights the achievements in exploring the rational design of dendrimers, partially marked by their macroscopic NLO performance.
基金The work was financially supported by the National Natural Science Foundation of China (Nos. 10104003, 10204003, 90206003, and 90101027) and the National Key Basic Research Special Foundation of China (No.TG1999075207).
文摘GaAs nanocrystals were prepared via a simple mechanical ball milling technique. The prepared GaAs nanocrystals have high purity and could form colloidal ethanol suspension without any surfactant additives. The colloidal GaAs nanocrystal suspension displayed excellent two-photon absorption property over the visible and near-infrared region from 490 nm to 1064 nm, which enables it to become a promising broadband optical limiting material.
基金Project supported by the National Natural Science Foundation of China （Grant No 60178025） and the Key Laboratory of 0ptoelectronics Information Technical Science of Ministry of Education, Institute of Modern 0ptics, Nankai University, China.
文摘This paper demonstrates an all-optical switching model system comprising a single pulsed pump beam at 355 nm and a CW He-Ne signal beam at 632.8 nm with 2-（2＇-hydroxyphenyl）benzothiazole （HBT） in ethanol solution. The origins of the optical switching effect were discussed. By the study of nonlinear optical properties for HBT in ethanol solvent, this paper verified that the excited-state intramolecular proton transfer （ESIPT） effect of HBT and the thermal effect of solvent worked on quite different time scales and together induced the change of the refractive index of HBT solution, leading to the signal beam deflection. The results indicated that the HBT molecule could be an excellent candidate for high-speed and high-sensitive optical switching devices.
文摘A novel tolane 4-methoxy-4'-nitro-diphenyl-acetylene (MONA) has been prepared quantitatively by reacting cuprous p-methoxy phenyl-acetylene with p-iodonitrobenzene. A single crystal of the Moan was grown by solution growth method. The crystal was then characterized by X-ray diffraction structure analysis and second-harmonic generation(SHG)investigation. Polymorphous crystal forms of the MONA were grown from different solvents having different nonlinear optical properties depending on their different crystal structures. The relationship between the crystal growth and crystal structure is discusse.
基金This research was supported by the National Natural Science Foundation (29476227) the Natural Science Foundation of Zhejiang Province (1999-299003).
文摘Synthesis of the third-order nonlinear materials: bis (1,4-dihydroxynaphthalene) tetrathiafulvalene and bis (1,4-dialkoxylnaphthalene) tetrathiafulvalene has been achieved in four steps, starting from 2,3-dichloro-1,4-naphthaquinone. The materials exhibit larger third-order nonlinear optical susceptibilities c(3) .
基金Project supported by the National Natural Science Foundation of China(51972208,51832007)。
文摘Nonlinear optical(NLO)crystals can be employed to expand the laser frequency and thus are of technical importance in advanced laser science.Noncentrosymmetric rare earth compounds keep attracting broad interest as a significant branch of NLO materials because the highly distorted structural motifs centered by rare earth ions could remarkably benefit the second harmonic generation.In this review,we proceed from structure-properties relationship and reveal the role of rare earth element in the optical properties of NLO materials.We believe that this work can deepen the understanding of rare earth-based NLO materials and provide some enlightenment for exploring novel practical NLO crystals.
