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 ef...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.展开更多
The linear and nonlinear optical absorption coefficients(ACs)and refraction index changes(RICs)of 1s-1p,1p-1d,and 1f-1d transitions are investigated in a wurtzite InxGa1-xN/GaN core-shell quantum dot(CSQD)with donor i...The linear and nonlinear optical absorption coefficients(ACs)and refraction index changes(RICs)of 1s-1p,1p-1d,and 1f-1d transitions are investigated in a wurtzite InxGa1-xN/GaN core-shell quantum dot(CSQD)with donor impurity by using density matrix approach.The effects of built-in electric field(BEF),ternary mixed crystal(TMC),impurity,and CSQD size are studied in detail.The finite element method is used to calculate the ground and excited energy state energy and wave function.The results reveal that the BEF has a great influence on the linear,nonlinear,and total ACs and RICs.The presence of impurity leads the resonant peaks of the ACs and RICs to be blue-shifted for all transitions,especially for 1s-1p transition.It is also found that the resonant peaks of the ACs and RICs present a red shift with In-composition decreasing or core radius increasing.Moreover,the amplitudes of the ACs and RICs are strongly affected by the incident optical intensity.The absorption saturation is more sensitive without the impurity than with the impurity,and the appearance of absorption saturation requires a larger incident optical intensity when considering the BEF.展开更多
Perovskite-structured barium strontium titanate[Ba_(1-x)Sr_(x)Ti O_(3),x=0.1–0.9] films have been epitaxially fabricated by using a pulsed-laser deposition technique.The third-order nonlinear optical properties were ...Perovskite-structured barium strontium titanate[Ba_(1-x)Sr_(x)Ti O_(3),x=0.1–0.9] films have been epitaxially fabricated by using a pulsed-laser deposition technique.The third-order nonlinear optical properties were studied through a z-scan method,allowing the resolution of the nonlinear refractive and absorptive contributions to the responses.Although all the samples show almost the same value of nonlinear absorption coefficient,the extracted nonlinear refractive index of the sample of x=0.3 is apparently larger than that of other samples.Dependency of the nonlinear optical properties on the Ba/Sr ratio is discussed in terms of the crystal phase transformation and metal-oxygen bond length of the selected materials.展开更多
In this paper, we report the experimental characterization of highly nonlinear Ge Sb S chalcogenide glass waveguides.We used a single-beam characterization protocol that accounts for the magnitude and sign of the real...In this paper, we report the experimental characterization of highly nonlinear Ge Sb S chalcogenide glass waveguides.We used a single-beam characterization protocol that accounts for the magnitude and sign of the real and imaginary parts of the third-order nonlinear susceptibility of integrated Ge23 Sb7 S70(GeSbS) chalcogenide glass waveguides in the near-infrared wavelength range at λ =1580 nm. We measured a waveguide nonlinear parameter of 7.0±0.7 W^(-1)· m(-1), which corresponds to a nonlinear refractive index of n_2=0.93±0.08 × 10^(-18) m^2∕W,comparable to that of silicon, but with an 80 times lower two-photon absorption coefficient βTPA=0.010± 0.003 cm∕GW, accompanied with linear propagation losses as low as 0.5 dB/cm. The outstanding linear and nonlinear properties of Ge Sb S, with a measured nonlinear figure of merit FOMTPA=6.0 ±1.4 at λ =1580 nm, ultimately make it one of the most promising integrated platforms for the realization of nonlinear functionalities.展开更多
A quantum chemical screening of two imidazole-based chalcone ligands: 2-</span></span><span><span><span style="font-family:""> </span></span></span><sp...A quantum chemical screening of two imidazole-based chalcone ligands: 2-</span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">[1-(3-(1H-imidazol-1-yl)propylimino)-3-(phenylallyl)]phenol and 2-</span></span></span><span><span><span style="font-family:"">[1-(3-(1H-</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">imidazol-1-yl)propylimino)-3-4-nitrophenylallyl]phenol (hereinafter ref</span></span></span><span><span><span style="font-family:"">erred to as HL1 and HL2 respectively) and their Pd, Pt and Zn chelates for charge transport and nonlinear optical (NLO) properties, is reported via dispersion-</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">corrected density functional theory (DFT-D3) and time-dependent DFT (TD-</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">DFT) methods. From our results, Pd and Pt complexes have been observed to show excellent hole-transport properties, owing to their very small reorgani<span>zation energies. The <span>light </span>extraction efficiency of the HL1-Pt complex was de</span>duced to be particularly impressive, thus suitable for the manufacture of <span>hole transport</span> layer in violet light emitting diodes (LEDs). Moreover, redox potentials and chemical stability studies have enabled us </span></span></span><span><span><span style="font-family:"">to </span></span></span><span><span><span style="font-family:"">validate the greater <span>stability in moisture (towards oxidation), of HL2 complexes compared to th</span>eir HL1 counterparts. The first and second hyperpolarizabilities of both ligands and their complexes have been found to be outstandingly higher than those of the push-pull prototypical, <span>para</span>-nitroaniline by factors of up to 12 in the case of HL2. These compounds, with the exception of the HL2-Pt complex, are thus interesting candidates having wide transparency tradeoffs for NLO efficiency in the manufacture of optoelectronic and photonic devices capable of second and third-order NLO response. Finally, metal chelation has been established to enhance the NLO response of all the chalcone-based imidazole ligands investigated as a result of metal-ligand charge transfer and ligand-</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">metal charge transfer electronic transitions identified in the resulting complexes with the exception of the zinc complexes.展开更多
The current study has obtained excellent potential nonlinear optical(NLO)materials by combining density functional theory methods with sum-over-states model to predict the second order NLO properties of helical graphe...The current study has obtained excellent potential nonlinear optical(NLO)materials by combining density functional theory methods with sum-over-states model to predict the second order NLO properties of helical graphene nanoribbons(HGNs)through introducing azulene defects or/and BN units.The introduction of these functional groups deforms the pristine HGN(compression or tension)and enhances obviously the static first hyperpolarizability(〈β0〉)of system by up to two orders of magnitude.The tensor components along the helical axis of HGNs play a dominant role in the total〈β0〉.The azulene defects and the BN units polarize the pristine HGN to different degrees,and the azulenes and contiguous benzenes are involved in the major electron excitations with significant contributions to〈β0〉but the BN units are not.The BN-doped chiral HGNs have good kinetic stability and strong second order NLO properties(6.84×10^(5)×10^(−30) esu),and can be a potential candidate of high-performance second order NLO materials.The predicted two-dimensional second order NLO spectra provide useful information for further exploration of those helicenes for electro-optic applications.展开更多
The substrate temperature(Ts)and N2 partial pressure(PN2)dependent optical and electrical properties of sputtered InGaZnON thin films are studied.With the increased Ts and PN2,the thin film becomes more crystallized a...The substrate temperature(Ts)and N2 partial pressure(PN2)dependent optical and electrical properties of sputtered InGaZnON thin films are studied.With the increased Ts and PN2,the thin film becomes more crystallized and nitrified.The Hall mobility,free carrier concentration(Ne),and electrical conductivity increase with the lowered interfacial potential barrier during crystal growing.The photoluminescence(PL)intensity decreases with the increased Ne.The band gap(Eg)narrows and the linear refractive index(n1)increases with the increasing concentration of N in the thin films.The Stokes shift between the PL peak and absorption edge decreases with Eg.The n1,dispersion energy,average oscillator wavelength,and oscillator length strength all increase with n1.The single oscillator energy decreases with n1.The nonlinear refractive index and third order optical susceptibility increase with n1.The Seebeck coefficient,electron effective mass,mean free path,scattering time,and plasma energy are all Ne dependent.展开更多
Functional materials with multiple properties are urgent to be explored to reach high requirements for applications nowadays.In this work,a new multifunctional one-dimensional(1D)chain compound[N(C_(3)H_(7))_(4)][Cu(o...Functional materials with multiple properties are urgent to be explored to reach high requirements for applications nowadays.In this work,a new multifunctional one-dimensional(1D)chain compound[N(C_(3)H_(7))_(4)][Cu(ohpma)]·H_(2)O 1(ohpma=deprotonated N-(2-hydoxyphenyl)oxamic acid)exhibiting both 1D antiferromagnetic and nonlinear optical properties,which are both originated from the same polar[Cu(C_(8)H_(4)NO_(4))]magnetic units,has been successfully synthesized by evaporation at room temperature.Bis-polydentate nature of the(ohpma)3−ligand with constrained tridentate and bidentate coordination sites conducts Cu^(2+)ions coordinating in different geometries and forms 1D chains along the c axis,which are further separated by the[N(C_(3)H_(7))_(4)]+cations.And the 1D magnetic chains further exhibit noncentrosymmetric polar arrangement.Nonlinear optical study shows polar compound 1 exhibits a discernible second-harmonic generation(SHG)efficiency and the calculation of the partial density of states indicates that the SHG efficiency of 1 is mainly originated from the polar[Cu(C_(8)H_(4)NO_(4))]magnetic units.Moreover,magnetic susceptibility shows a broad maximum around 70 K with strong intrachain interaction of J/k B=−113.0 K but no long-range order is observed down to 2 K,suggesting that 1 shows a good 1D magnetism.Both good 1D magnetism and SHG activity suggest that 1 could be as a potential multifunctional material,particularly.展开更多
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...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 10<sup>7</sup> atomic units (10<sup><span style="color:#4F4F4F;font-family:-apple-system, " font-size:14px;white-space:normal;background-color:#ffffff;"="">-</span>33</sup> 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(CH<sub>3</sub>)<sub>2</sub> or -NHCH<sub>3</sub>) in the azobenzene ring, so that the third-order NLO materials with good performance can be obtained.展开更多
In the framework of the Thomas–Fermi(TF) approach, a model for the p-type double-δ-doped(DDD) system in Ga As is presented. This model, unlike other works in the literature, takes into account that the Poisson equat...In the framework of the Thomas–Fermi(TF) approach, a model for the p-type double-δ-doped(DDD) system in Ga As is presented. This model, unlike other works in the literature, takes into account that the Poisson equation associated with the system is nonlinear. The electronic structure is calculated for heavy and light holes. The changes in the electronic structure result of the distance d between the doped layers are studied. In particular, the relative absorption coefficient as well as the relative refractive index change is calculated as a function of the incident photon energy for heavy holes. The effect of the interlayer distance exhibits, in the absorption coefficient, a red shift of the peak position and a decrease in amplitude when the distance increases. In addition, the relative refractive index change node has a red shift as well as the interlayer distance increases. The calculations show that the effect of the separation between layers has a greater influence on the linear terms. These results are very important for theoretical calculations and engineering of optical and electronic devices based in δ-doped Ga As.展开更多
Fabrication of metal-organic frameworks(MOFs)thin films has been an efficient way to expand their functionalities and applications.Here,we use the vapor-assisted deposition(VAD)method to epitaxially grow a porphyrin-b...Fabrication of metal-organic frameworks(MOFs)thin films has been an efficient way to expand their functionalities and applications.Here,we use the vapor-assisted deposition(VAD)method to epitaxially grow a porphyrin-based MOF PCN-222 film.That is,vapor source assists to deposit pre-treated precursor solution on quartz substrate to form a continuous PCN-222 film.Furthermore,utilizing the post-treated encapsulation of functional carbon-based nanoparticles,the carbon nanodots(CND)and Pt doped CND(Pt/CND)are well loaded into the pores of PCN-222 film,the size(~3.1 nm)of which is highly close to the pore size of the corresponding MOF(~3.7 nm).The Z-scan results reveal that PCN-222 film exhibits high reverse saturable absorption.In addition,encapsulation of carbon based nanodots into PCN-222 film could enhance the nonlinear optical limiting effect benefiting from the host-guest combination.This study serves to present both the available toolbox of thin film preparation and high potential for precise synthetic nanocomposite films in optical limiting devices.展开更多
We consider the effects of quantum dot radius,confinement potential depth and controllable effective mass on the optical rectification coefficient(ORC)in spherical quantum dots,which is confined with Modified Kratzer-...We consider the effects of quantum dot radius,confinement potential depth and controllable effective mass on the optical rectification coefficient(ORC)in spherical quantum dots,which is confined with Modified Kratzer-Coulomb Potential(MKCP).Using the Nikiforov-Uvarov method and compact density matrix theory,the ground state energy,ORC and wave function of electrons under the combined action of many factors are calculated.The results show that they affect the optical rectification response from different angles,including the position of peak and formant.展开更多
As one of the greatest inventions in the 20 th century, ultrafast lasers have offered new opportunities in the areas of basic scientific research and industrial manufacturing. Optical modulators are of great importanc...As one of the greatest inventions in the 20 th century, ultrafast lasers have offered new opportunities in the areas of basic scientific research and industrial manufacturing. Optical modulators are of great importance in ultrafast lasers, which directly affect the output laser performances. Over the past decades, significant efforts have been made in the development of compact, controllable, repeatable, as well as integratable optical modulators(i.e., saturable absorbers). In this paper, we review the fundamentals of the most widely studied saturable absorbers, including semiconductor saturable absorber mirrors and low-dimensional nanomaterials. Then, different fabrication technologies for saturable absorbers and their ultrafast laser applications in a wide wavelength range are illustrated. Furthermore, challenges and perspectives for the future development of saturable absorbers are discussed and presented. The development of ultrafast lasers together with the continuous exploration of reliable saturable absorbers will open up new directions for the mass production of the nextgeneration optoelectronic devices.展开更多
We report VO_(x)/NaVO_(3) nanocomposite as a novel saturable absorber for the first time,to the best of our knowledge.The efficient nonlinear absorption coefficient and the modulation depth are determined by the Z-sca...We report VO_(x)/NaVO_(3) nanocomposite as a novel saturable absorber for the first time,to the best of our knowledge.The efficient nonlinear absorption coefficient and the modulation depth are determined by the Z-scan technology.As a saturable absorber,a passively Q-switched Nd-doped bulk laser at 1.34μm is demonstrated,producing the shortest pulse duration of 129 ns at a repetition rate of 274 kHz.In the passively Q-switched Tm:YLF laser with the prepared saturable absorber,the shortest pulse duration was 292 ns with a repetition rate of 155 kHz.Our work confirmed the saturable absorption in VO_(x)/NaVO_(3) for possible optical modulation in the near-infrared region.展开更多
基金Project supported by the Natural Science Foundation of Anhui Province(Grant No.1908085MA12)the National Natural Science Foundation of China(Grant No.21703222)。
文摘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.
基金the National Natural Science Foundation of China(Grant No.11947414)the Research Program of Science and Technology at University of Inner Mongolia Autonomous Region,China(Grant No.NJZZ19001).
文摘The linear and nonlinear optical absorption coefficients(ACs)and refraction index changes(RICs)of 1s-1p,1p-1d,and 1f-1d transitions are investigated in a wurtzite InxGa1-xN/GaN core-shell quantum dot(CSQD)with donor impurity by using density matrix approach.The effects of built-in electric field(BEF),ternary mixed crystal(TMC),impurity,and CSQD size are studied in detail.The finite element method is used to calculate the ground and excited energy state energy and wave function.The results reveal that the BEF has a great influence on the linear,nonlinear,and total ACs and RICs.The presence of impurity leads the resonant peaks of the ACs and RICs to be blue-shifted for all transitions,especially for 1s-1p transition.It is also found that the resonant peaks of the ACs and RICs present a red shift with In-composition decreasing or core radius increasing.Moreover,the amplitudes of the ACs and RICs are strongly affected by the incident optical intensity.The absorption saturation is more sensitive without the impurity than with the impurity,and the appearance of absorption saturation requires a larger incident optical intensity when considering the BEF.
基金supported by the National Natural Science Foundation of China(No.10704065)the Graduate Innovation Foundation of Yantai University(No.KGIFYTU2212)。
文摘Perovskite-structured barium strontium titanate[Ba_(1-x)Sr_(x)Ti O_(3),x=0.1–0.9] films have been epitaxially fabricated by using a pulsed-laser deposition technique.The third-order nonlinear optical properties were studied through a z-scan method,allowing the resolution of the nonlinear refractive and absorptive contributions to the responses.Although all the samples show almost the same value of nonlinear absorption coefficient,the extracted nonlinear refractive index of the sample of x=0.3 is apparently larger than that of other samples.Dependency of the nonlinear optical properties on the Ba/Sr ratio is discussed in terms of the crystal phase transformation and metal-oxygen bond length of the selected materials.
基金H2020 European Research Council(ERC)(647342)U.S. National Science Foundation(NSF)(1506605)French RENATECH Network
文摘In this paper, we report the experimental characterization of highly nonlinear Ge Sb S chalcogenide glass waveguides.We used a single-beam characterization protocol that accounts for the magnitude and sign of the real and imaginary parts of the third-order nonlinear susceptibility of integrated Ge23 Sb7 S70(GeSbS) chalcogenide glass waveguides in the near-infrared wavelength range at λ =1580 nm. We measured a waveguide nonlinear parameter of 7.0±0.7 W^(-1)· m(-1), which corresponds to a nonlinear refractive index of n_2=0.93±0.08 × 10^(-18) m^2∕W,comparable to that of silicon, but with an 80 times lower two-photon absorption coefficient βTPA=0.010± 0.003 cm∕GW, accompanied with linear propagation losses as low as 0.5 dB/cm. The outstanding linear and nonlinear properties of Ge Sb S, with a measured nonlinear figure of merit FOMTPA=6.0 ±1.4 at λ =1580 nm, ultimately make it one of the most promising integrated platforms for the realization of nonlinear functionalities.
文摘A quantum chemical screening of two imidazole-based chalcone ligands: 2-</span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">[1-(3-(1H-imidazol-1-yl)propylimino)-3-(phenylallyl)]phenol and 2-</span></span></span><span><span><span style="font-family:"">[1-(3-(1H-</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">imidazol-1-yl)propylimino)-3-4-nitrophenylallyl]phenol (hereinafter ref</span></span></span><span><span><span style="font-family:"">erred to as HL1 and HL2 respectively) and their Pd, Pt and Zn chelates for charge transport and nonlinear optical (NLO) properties, is reported via dispersion-</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">corrected density functional theory (DFT-D3) and time-dependent DFT (TD-</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">DFT) methods. From our results, Pd and Pt complexes have been observed to show excellent hole-transport properties, owing to their very small reorgani<span>zation energies. The <span>light </span>extraction efficiency of the HL1-Pt complex was de</span>duced to be particularly impressive, thus suitable for the manufacture of <span>hole transport</span> layer in violet light emitting diodes (LEDs). Moreover, redox potentials and chemical stability studies have enabled us </span></span></span><span><span><span style="font-family:"">to </span></span></span><span><span><span style="font-family:"">validate the greater <span>stability in moisture (towards oxidation), of HL2 complexes compared to th</span>eir HL1 counterparts. The first and second hyperpolarizabilities of both ligands and their complexes have been found to be outstandingly higher than those of the push-pull prototypical, <span>para</span>-nitroaniline by factors of up to 12 in the case of HL2. These compounds, with the exception of the HL2-Pt complex, are thus interesting candidates having wide transparency tradeoffs for NLO efficiency in the manufacture of optoelectronic and photonic devices capable of second and third-order NLO response. Finally, metal chelation has been established to enhance the NLO response of all the chalcone-based imidazole ligands investigated as a result of metal-ligand charge transfer and ligand-</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:"">metal charge transfer electronic transitions identified in the resulting complexes with the exception of the zinc complexes.
基金supported by the National Natural Science Foundation of China(No.21673025)the Open Projects of the Key Laboratory of Polyoxometalate Science of Ministry of Education(NENU),China and the Project of the State Key Laboratory of Supramolecular Structure and Materials(JLU),China(No.SKLSSM2021020).
文摘The current study has obtained excellent potential nonlinear optical(NLO)materials by combining density functional theory methods with sum-over-states model to predict the second order NLO properties of helical graphene nanoribbons(HGNs)through introducing azulene defects or/and BN units.The introduction of these functional groups deforms the pristine HGN(compression or tension)and enhances obviously the static first hyperpolarizability(〈β0〉)of system by up to two orders of magnitude.The tensor components along the helical axis of HGNs play a dominant role in the total〈β0〉.The azulene defects and the BN units polarize the pristine HGN to different degrees,and the azulenes and contiguous benzenes are involved in the major electron excitations with significant contributions to〈β0〉but the BN units are not.The BN-doped chiral HGNs have good kinetic stability and strong second order NLO properties(6.84×10^(5)×10^(−30) esu),and can be a potential candidate of high-performance second order NLO materials.The predicted two-dimensional second order NLO spectra provide useful information for further exploration of those helicenes for electro-optic applications.
基金Project supported by the National Natural Science Foundation of China(Grant No.61674107)Shenzhen Key Lab Fund,China(Grant No.ZDSYS20170228105421966)Science and Technology Plan of Shenzhen,China(Grant No.JCYJ20170302150335518)
文摘The substrate temperature(Ts)and N2 partial pressure(PN2)dependent optical and electrical properties of sputtered InGaZnON thin films are studied.With the increased Ts and PN2,the thin film becomes more crystallized and nitrified.The Hall mobility,free carrier concentration(Ne),and electrical conductivity increase with the lowered interfacial potential barrier during crystal growing.The photoluminescence(PL)intensity decreases with the increased Ne.The band gap(Eg)narrows and the linear refractive index(n1)increases with the increasing concentration of N in the thin films.The Stokes shift between the PL peak and absorption edge decreases with Eg.The n1,dispersion energy,average oscillator wavelength,and oscillator length strength all increase with n1.The single oscillator energy decreases with n1.The nonlinear refractive index and third order optical susceptibility increase with n1.The Seebeck coefficient,electron effective mass,mean free path,scattering time,and plasma energy are all Ne dependent.
基金supported by the National Natural Science Foundation of China(NSFC,No.22101091)the Fundamental Research Funds for the Central Universities(No.2019kfyXKJC016)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(No.B210003),Knowledge Innovation Program of Wuhan-Basic Research.
文摘Functional materials with multiple properties are urgent to be explored to reach high requirements for applications nowadays.In this work,a new multifunctional one-dimensional(1D)chain compound[N(C_(3)H_(7))_(4)][Cu(ohpma)]·H_(2)O 1(ohpma=deprotonated N-(2-hydoxyphenyl)oxamic acid)exhibiting both 1D antiferromagnetic and nonlinear optical properties,which are both originated from the same polar[Cu(C_(8)H_(4)NO_(4))]magnetic units,has been successfully synthesized by evaporation at room temperature.Bis-polydentate nature of the(ohpma)3−ligand with constrained tridentate and bidentate coordination sites conducts Cu^(2+)ions coordinating in different geometries and forms 1D chains along the c axis,which are further separated by the[N(C_(3)H_(7))_(4)]+cations.And the 1D magnetic chains further exhibit noncentrosymmetric polar arrangement.Nonlinear optical study shows polar compound 1 exhibits a discernible second-harmonic generation(SHG)efficiency and the calculation of the partial density of states indicates that the SHG efficiency of 1 is mainly originated from the polar[Cu(C_(8)H_(4)NO_(4))]magnetic units.Moreover,magnetic susceptibility shows a broad maximum around 70 K with strong intrachain interaction of J/k B=−113.0 K but no long-range order is observed down to 2 K,suggesting that 1 shows a good 1D magnetism.Both good 1D magnetism and SHG activity suggest that 1 could be as a potential multifunctional material,particularly.
文摘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 10<sup>7</sup> atomic units (10<sup><span style="color:#4F4F4F;font-family:-apple-system, " font-size:14px;white-space:normal;background-color:#ffffff;"="">-</span>33</sup> 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(CH<sub>3</sub>)<sub>2</sub> or -NHCH<sub>3</sub>) in the azobenzene ring, so that the third-order NLO materials with good performance can be obtained.
基金Project supported by PISA 2016–1 UJAT and PRODEP Folio UJAT-245 of México
文摘In the framework of the Thomas–Fermi(TF) approach, a model for the p-type double-δ-doped(DDD) system in Ga As is presented. This model, unlike other works in the literature, takes into account that the Poisson equation associated with the system is nonlinear. The electronic structure is calculated for heavy and light holes. The changes in the electronic structure result of the distance d between the doped layers are studied. In particular, the relative absorption coefficient as well as the relative refractive index change is calculated as a function of the incident photon energy for heavy holes. The effect of the interlayer distance exhibits, in the absorption coefficient, a red shift of the peak position and a decrease in amplitude when the distance increases. In addition, the relative refractive index change node has a red shift as well as the interlayer distance increases. The calculations show that the effect of the separation between layers has a greater influence on the linear terms. These results are very important for theoretical calculations and engineering of optical and electronic devices based in δ-doped Ga As.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000)the National Key Research and Development Program of China(2018YFA0208600)+1 种基金the National Natural Science Foundation of China(21872148,21601189)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2018339)。
文摘Fabrication of metal-organic frameworks(MOFs)thin films has been an efficient way to expand their functionalities and applications.Here,we use the vapor-assisted deposition(VAD)method to epitaxially grow a porphyrin-based MOF PCN-222 film.That is,vapor source assists to deposit pre-treated precursor solution on quartz substrate to form a continuous PCN-222 film.Furthermore,utilizing the post-treated encapsulation of functional carbon-based nanoparticles,the carbon nanodots(CND)and Pt doped CND(Pt/CND)are well loaded into the pores of PCN-222 film,the size(~3.1 nm)of which is highly close to the pore size of the corresponding MOF(~3.7 nm).The Z-scan results reveal that PCN-222 film exhibits high reverse saturable absorption.In addition,encapsulation of carbon based nanodots into PCN-222 film could enhance the nonlinear optical limiting effect benefiting from the host-guest combination.This study serves to present both the available toolbox of thin film preparation and high potential for precise synthetic nanocomposite films in optical limiting devices.
基金Project supported by Support National Natural Science Foundation of China(Grant Nos.52174161,12174161,51702003,61775087,and 11674312)the Natural Science Foundation of Anhui Province(No.1508085QF140)Plan Fund for Outstanding Young Talents in Colleges and Universities(No.gxyq ZD2018039)。
文摘We consider the effects of quantum dot radius,confinement potential depth and controllable effective mass on the optical rectification coefficient(ORC)in spherical quantum dots,which is confined with Modified Kratzer-Coulomb Potential(MKCP).Using the Nikiforov-Uvarov method and compact density matrix theory,the ground state energy,ORC and wave function of electrons under the combined action of many factors are calculated.The results show that they affect the optical rectification response from different angles,including the position of peak and formant.
基金supported by the National Natural Science Foundation of China (Nos.61905148,61775146,and 12074264)the Shenzhen Science and Technology Project (Nos.JCYJ20190808160205460,JCYJ20190808174201658,and JCYJ20190808141011530)。
文摘As one of the greatest inventions in the 20 th century, ultrafast lasers have offered new opportunities in the areas of basic scientific research and industrial manufacturing. Optical modulators are of great importance in ultrafast lasers, which directly affect the output laser performances. Over the past decades, significant efforts have been made in the development of compact, controllable, repeatable, as well as integratable optical modulators(i.e., saturable absorbers). In this paper, we review the fundamentals of the most widely studied saturable absorbers, including semiconductor saturable absorber mirrors and low-dimensional nanomaterials. Then, different fabrication technologies for saturable absorbers and their ultrafast laser applications in a wide wavelength range are illustrated. Furthermore, challenges and perspectives for the future development of saturable absorbers are discussed and presented. The development of ultrafast lasers together with the continuous exploration of reliable saturable absorbers will open up new directions for the mass production of the nextgeneration optoelectronic devices.
基金supported by the National Natural Science Foundation of China (Nos. 12174223, 12004213, 21872084, and 62175128)the Young Scholar Program of Shandong University for the financial support
文摘We report VO_(x)/NaVO_(3) nanocomposite as a novel saturable absorber for the first time,to the best of our knowledge.The efficient nonlinear absorption coefficient and the modulation depth are determined by the Z-scan technology.As a saturable absorber,a passively Q-switched Nd-doped bulk laser at 1.34μm is demonstrated,producing the shortest pulse duration of 129 ns at a repetition rate of 274 kHz.In the passively Q-switched Tm:YLF laser with the prepared saturable absorber,the shortest pulse duration was 292 ns with a repetition rate of 155 kHz.Our work confirmed the saturable absorption in VO_(x)/NaVO_(3) for possible optical modulation in the near-infrared region.