Institute of Crystal Materials and State Key Laboratory of Crystal Materials,Shandong University,Ji'nan 250100(Received 18 March 2000)The data of the thermal expansion and specific heat of cadmium mercury thiocyan...Institute of Crystal Materials and State Key Laboratory of Crystal Materials,Shandong University,Ji'nan 250100(Received 18 March 2000)The data of the thermal expansion and specific heat of cadmium mercury thiocyanate crystal have been obtained.The specific heat is 0.7588J/g℃at room temperature.The thermal expansion occurs in the direction parallel to the c-axis,and the thermal contraction occurs in the direction parallel to the a-axis.The thermal expansion is the same as the thermal contraction at 353 K.The relationship between thermal properties and crystal structure is discussed.展开更多
During the process of KDP crystal growth, metal ions strongly affect the growth habit and optical properties of KDP single crystal. In this paper, KDP crystals were grown from an aqueous solution doped with different ...During the process of KDP crystal growth, metal ions strongly affect the growth habit and optical properties of KDP single crystal. In this paper, KDP crystals were grown from an aqueous solution doped with different concentration of Fe^3+ dopant by traditional temperaturereduction method and "point-seed" rapid growth method. Furthermore, we examined the light scatter and measured the transmission of these KDP crystals. It is found that the dopant of Fe^3+ ion can improve the stability of the KDP growth solution when its concentration is less than 30 ppm. The effects of Fe^3+ ion on the growth habit and optical properties of KDP crystal are also obvious.展开更多
The nonlinear optical properties of a perfectly polarized KIO^single crystal were investigated.The principal refractive indices and nonlinear optical coefficients have been measured.The results are as follows:n1=1.696...The nonlinear optical properties of a perfectly polarized KIO^single crystal were investigated.The principal refractive indices and nonlinear optical coefficients have been measured.The results are as follows:n1=1.6967,n2=1-8329,n3=1.8358 for 0.5893μm;d_(31)=1.2|d_(31)(LiIO_(3))|,d_(32)=1.8|d_(31)(LiIO_(3))|.The in tensity of the frequency-doubled light of the KIO_(3 )single crystal with 2.96 mm thickness is 1.2 times as large as that of the KTP single crystal with the same thickness.展开更多
The geometric structure,electronic structure,and optical properties of CdHg(SCN)4 crystal are calculated by using the density functional perturbation theory and Green function screening Coulomb interaction approxima...The geometric structure,electronic structure,and optical properties of CdHg(SCN)4 crystal are calculated by using the density functional perturbation theory and Green function screening Coulomb interaction approximation.The band gap of CdHg(SCN)4 crystal is calculated to be 3.198 eV,which is in good agreement with the experimental value 3.265 eV.The calculated second-order nonlinear optical coefficients are d14 = 1.2906 pm/V and d15 = 5.0928 pm/V,which are in agreement with the experimental results(d14=(1.4 ±0.6) pm/V and d15=(6.0 ±0.9) pm/V).Moreover,it is found that the contribution to the valence band mainly comes from Cd-4d,Hg-5d states,and the contributions to the valence band top and the conduction band bottom predominantly come from C-2p,N-2p,and S-3p states.The second-order nonlinear optical effect of CdHg(SCN)_4 crystal results mainly from the internal electronic transition of(SCN)^-.展开更多
A new ternary photopolymer system is used in fabricating photonic crystals (PhCs) with controlled defects by combination of single-photon and two-photon photopolymerization. The former process can produce PhCs in on...A new ternary photopolymer system is used in fabricating photonic crystals (PhCs) with controlled defects by combination of single-photon and two-photon photopolymerization. The former process can produce PhCs in one-step recording with a low-power (tens mW) continuous-wave laser at 532nm, while the latter can create desired defects. The preparation of the material, the optical setup and the preliminary experimental results are given. Compared with other methods, this approach is much more accessible and convenient for use of visible light and has advantages of making PhCs in a large scale quickly and economicaJly and introducing any defects exactly, especially for three-dimensional structures.展开更多
A series of Nb doped KTP crystals are grown with seed Aux method and Hux pulling method.The results of our investigation on growth,morphology defects of the crystals are reported in this paper.We obtained the relation...A series of Nb doped KTP crystals are grown with seed Aux method and Hux pulling method.The results of our investigation on growth,morphology defects of the crystals are reported in this paper.We obtained the relationship between Nb contents and second-harmonic generation angles of the crystals.Noncritical phase matching has been realized by 4%Nb doped KTP crystal for Nd:YAG laser 1.06μm output.展开更多
Volume compensation(VC)achieved in(Lu,Nd):YAl_(3)(BO_(3))_(4)(YAB)crystal codoped with Lu^(3+)and Nd^(3+)ions is described.The lattice parameters,spectral properties and laser performances of the VC(Lu,Nd):YAB and sin...Volume compensation(VC)achieved in(Lu,Nd):YAl_(3)(BO_(3))_(4)(YAB)crystal codoped with Lu^(3+)and Nd^(3+)ions is described.The lattice parameters,spectral properties and laser performances of the VC(Lu,Nd):YAB and single-doped Nd:YAB(NYAB)crystals are measured and compared.The results indicate that the laser performances of NYAB crystal can be greatly improved by the VC doping.展开更多
GaP nanocrystals were synthesized by both the organic solvent reflux and high temperature high pressure benzene thermal synthesis methods.The effect of organic solvent on the optical absorption properties of GaP nanoc...GaP nanocrystals were synthesized by both the organic solvent reflux and high temperature high pressure benzene thermal synthesis methods.The effect of organic solvent on the optical absorption properties of GaP nanocrystals were studied.The results show that crystal grains of the sample synthesized by the latter method have better quality and uniformity.The solvents which consist of polar molecules and form strong chemical bonds with Ga atoms cause obvious redshift of the absorption spectra of GaP nanocrystals.The absorption spectra redshift much more if the solvent molecules have π electrons which involved in the formation of complex bond between Ga atoms and solvent molecules.展开更多
Cd_(x)(Sr_(0.61)Ba_(0.39))_(1-x)Nb_(2)O_(6)(CdSBN)crystals have been grown successfully by Czochralski technique.The difficulty in crystal growth increased with the increase of the crystal diameter.Macroscopic defects...Cd_(x)(Sr_(0.61)Ba_(0.39))_(1-x)Nb_(2)O_(6)(CdSBN)crystals have been grown successfully by Czochralski technique.The difficulty in crystal growth increased with the increase of the crystal diameter.Macroscopic defects,such as striations and crackings were observed in some crystals.Temperature dependence of dielectric constant ε′γ3 and pyroelectric coefficient P were studied.The relationship between grown behavior and melt compositions was also discussed.展开更多
Tb-doped SBN crystals were prepared by the Czochralski technique.Their dielectric,ferroelectric,and pyroelectric properties were studied.A low temperature phase transition between two polar phases was revealed by the ...Tb-doped SBN crystals were prepared by the Czochralski technique.Their dielectric,ferroelectric,and pyroelectric properties were studied.A low temperature phase transition between two polar phases was revealed by the anomalies of the dielectric and pyroelectric properties;the polar axis changes its direction during this transition.The point group of the low temperature phase may be mm2,m or 1.展开更多
Two coherent or incoherent stable self-pumped phase conjugations have been obtained simultaneously in a Ce-doped(K_(0.5)Na_(0.5))_(2y)(Sr_(0.61)Ba_(0.39))_(1-y) Nb_(2)O_(6)(KNSBN)crystal by using two mutually coherent...Two coherent or incoherent stable self-pumped phase conjugations have been obtained simultaneously in a Ce-doped(K_(0.5)Na_(0.5))_(2y)(Sr_(0.61)Ba_(0.39))_(1-y) Nb_(2)O_(6)(KNSBN)crystal by using two mutually coherent input beams from a He-Ne laser,and energy translation from one beam to another induces self-pumped phase conjugative reflectivity of one beam above 100%.展开更多
The Cu-doped'KNSBN crystals have been grown.The self-pumped phase conjugate mirrors of Cu-doped KNSBN crystals have been demonstrated.The phase conjugate reflectivity reaches as high as 68% for the crystal with 0....The Cu-doped'KNSBN crystals have been grown.The self-pumped phase conjugate mirrors of Cu-doped KNSBN crystals have been demonstrated.The phase conjugate reflectivity reaches as high as 68% for the crystal with 0.04 wt.%Cu-doped.The phase conjugate reflectivity and its response time were also measured as a function of the argon-ion laser wavelengths.展开更多
Striation-free LiBa_(2)Nb_(5)O_(15)(LBN)single crystal of good optical quality has been grown by Czochralski method.The crystal growth and dielectric,structural,spectral properties of LBN were measured.Experimental re...Striation-free LiBa_(2)Nb_(5)O_(15)(LBN)single crystal of good optical quality has been grown by Czochralski method.The crystal growth and dielectric,structural,spectral properties of LBN were measured.Experimental results show that LBN single crystal belongs to tetragonal tungsten bronze structure at room temperature.Experiments carried out with LBN powder samples have shown that this crystal has good second harmonic generation effect.At room temperature,the dielectric constant ε_(33) is about 87 and Curie temperature T_(c),is about 586℃.A very ideal uniaxial conoscope image can be observed in LBN single crystal under polarizing microscope.In the range of 600 to 2600nm,the transmission of single crystal is about 75%.展开更多
This paper reports the growth of pqre and Na,K modified lead barium niobate crystals and the measurement of their dielectric and structure properties.Exprimental results show that both pure and Na,K modified lead bari...This paper reports the growth of pqre and Na,K modified lead barium niobate crystals and the measurement of their dielectric and structure properties.Exprimental results show that both pure and Na,K modified lead barium niobate crystals have growth striations.All the crystals belong to 4mm point group of tetragonal system at room temperature.Their Curie temperature are 379℃,389℃ and 473℃,respectively.展开更多
In this paper,by comparing the three possible combinations of the basic structure unit TiO_(6) octahedra,a simple model is proposed to explain the cause of the formation of the bicrystal structure in KTiOPO_(4)(KTP)cr...In this paper,by comparing the three possible combinations of the basic structure unit TiO_(6) octahedra,a simple model is proposed to explain the cause of the formation of the bicrystal structure in KTiOPO_(4)(KTP)crystals.The theoretical morphology of KTP crystal is studied and the rate of the appearance possibilities of different faces are obtained.The relationships between bicrystal structure and crystal properties are discussed.展开更多
Using dye laser as pumping light source,we have first realized on NYAB crystal the laser self-frequency doubling run from 1.06μm to 0.53μm.The threshold energy is less than 4mJ;conversion efficiency is 6.2%,and the ...Using dye laser as pumping light source,we have first realized on NYAB crystal the laser self-frequency doubling run from 1.06μm to 0.53μm.The threshold energy is less than 4mJ;conversion efficiency is 6.2%,and the self-frequency-doubling green light output energy is 2.5mJ.展开更多
Potasium sodium lead barium niobate KNPBN crystals have been grown successfully by flux method.The dielectric constant along the polar axis was measured at 50 kHz as a function of temperature in the range of 0 to 400...Potasium sodium lead barium niobate KNPBN crystals have been grown successfully by flux method.The dielectric constant along the polar axis was measured at 50 kHz as a function of temperature in the range of 0 to 400℃.The flux system,diffuse phase transition and optical absorption were also discussed.展开更多
Susceptibility measurements on Bi_(2)Sr_(2)CaCu_(2)O_(8) single crystals do reveal field-induced-suppression of sharp phase transition.No apparent anisotropy of the susceptibility was observed when magnetic field was ...Susceptibility measurements on Bi_(2)Sr_(2)CaCu_(2)O_(8) single crystals do reveal field-induced-suppression of sharp phase transition.No apparent anisotropy of the susceptibility was observed when magnetic field was applied along the three main directions a,b and c.The three dimensional isotropic fluctuation diamagnetism theory is proposed to explain our experimental finding of isotropic susceptibility.In a wide range of magnetic field,the temperature dependence of susceptibility does not show any obvious change in its character when the sample enters into expected vortex-lattice state from vortex-liquid state.展开更多
A potassium lithium niobate crystal with tetragonal tungsten bronze structure was prepared by the Czochralski technique.The dielectric and pyroelectric properties were investigated in the temperature range of 300 to 1...A potassium lithium niobate crystal with tetragonal tungsten bronze structure was prepared by the Czochralski technique.The dielectric and pyroelectric properties were investigated in the temperature range of 300 to 10 K.A broadened ferroelectric-ferroelectric transition between phases with space group 4mm and space group m was found at about 80K.展开更多
By flux method,potassium tantalate niobate crystals with 46%Nb contents were prepared.In this material 90°a-type domains with(011)and(01ī)walls were observed by a transmission electron microscope,and the nature ...By flux method,potassium tantalate niobate crystals with 46%Nb contents were prepared.In this material 90°a-type domains with(011)and(01ī)walls were observed by a transmission electron microscope,and the nature of fringe patterns associated with these domain walls was analysed.According to the extinction rules for the domain walls,the displacement vector R along<01ī>direction can be determined.Finally,using a selected area electron diffraction method,we examined the crystallographic character of these 90°domains and defined the ratio of lattice parameters c to a.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.69890230 and 69778023the Scientific Research Foundation for Outstanding Young Scientists of Shandong Province of China.
文摘Institute of Crystal Materials and State Key Laboratory of Crystal Materials,Shandong University,Ji'nan 250100(Received 18 March 2000)The data of the thermal expansion and specific heat of cadmium mercury thiocyanate crystal have been obtained.The specific heat is 0.7588J/g℃at room temperature.The thermal expansion occurs in the direction parallel to the c-axis,and the thermal contraction occurs in the direction parallel to the a-axis.The thermal expansion is the same as the thermal contraction at 353 K.The relationship between thermal properties and crystal structure is discussed.
基金the State High Technology Program for Inertial Confinement Fusion and National Science Foundation (No.59823003)Project of United Foundation (No.10676019)Youth Scientist Fund of Shandong Province (Nos. 2004BS04022 and 03BS079)
文摘During the process of KDP crystal growth, metal ions strongly affect the growth habit and optical properties of KDP single crystal. In this paper, KDP crystals were grown from an aqueous solution doped with different concentration of Fe^3+ dopant by traditional temperaturereduction method and "point-seed" rapid growth method. Furthermore, we examined the light scatter and measured the transmission of these KDP crystals. It is found that the dopant of Fe^3+ ion can improve the stability of the KDP growth solution when its concentration is less than 30 ppm. The effects of Fe^3+ ion on the growth habit and optical properties of KDP crystal are also obvious.
文摘The nonlinear optical properties of a perfectly polarized KIO^single crystal were investigated.The principal refractive indices and nonlinear optical coefficients have been measured.The results are as follows:n1=1.6967,n2=1-8329,n3=1.8358 for 0.5893μm;d_(31)=1.2|d_(31)(LiIO_(3))|,d_(32)=1.8|d_(31)(LiIO_(3))|.The in tensity of the frequency-doubled light of the KIO_(3 )single crystal with 2.96 mm thickness is 1.2 times as large as that of the KTP single crystal with the same thickness.
基金supported by the National Natural Science Foundation of China(Grant No.51372140)the Youth Scientist Fund of Shandong Province,China(Grant No.BS2011CL025)the Basic Discipline Research Fund of China University of Petroleum,Beijing,China(Grant No.01JB0169)
文摘The geometric structure,electronic structure,and optical properties of CdHg(SCN)4 crystal are calculated by using the density functional perturbation theory and Green function screening Coulomb interaction approximation.The band gap of CdHg(SCN)4 crystal is calculated to be 3.198 eV,which is in good agreement with the experimental value 3.265 eV.The calculated second-order nonlinear optical coefficients are d14 = 1.2906 pm/V and d15 = 5.0928 pm/V,which are in agreement with the experimental results(d14=(1.4 ±0.6) pm/V and d15=(6.0 ±0.9) pm/V).Moreover,it is found that the contribution to the valence band mainly comes from Cd-4d,Hg-5d states,and the contributions to the valence band top and the conduction band bottom predominantly come from C-2p,N-2p,and S-3p states.The second-order nonlinear optical effect of CdHg(SCN)_4 crystal results mainly from the internal electronic transition of(SCN)^-.
基金Supported by the National Basic Research Programme of China under Grant No 2004CB719803. NSFC/RGC (50218001). the National Natural Science Foundation of China under Grant Nos 60477005. 50173015, 60377041, and 60677026, and the Natural Science Foundation of Shandong Province (Y2006A09).
文摘A new ternary photopolymer system is used in fabricating photonic crystals (PhCs) with controlled defects by combination of single-photon and two-photon photopolymerization. The former process can produce PhCs in one-step recording with a low-power (tens mW) continuous-wave laser at 532nm, while the latter can create desired defects. The preparation of the material, the optical setup and the preliminary experimental results are given. Compared with other methods, this approach is much more accessible and convenient for use of visible light and has advantages of making PhCs in a large scale quickly and economicaJly and introducing any defects exactly, especially for three-dimensional structures.
基金Supported by a grant for Research Project in Climbing Program from the Science and Technology Commission of China.
文摘A series of Nb doped KTP crystals are grown with seed Aux method and Hux pulling method.The results of our investigation on growth,morphology defects of the crystals are reported in this paper.We obtained the relationship between Nb contents and second-harmonic generation angles of the crystals.Noncritical phase matching has been realized by 4%Nb doped KTP crystal for Nd:YAG laser 1.06μm output.
基金Supported by the National Natural Science Foundation of China.
文摘Volume compensation(VC)achieved in(Lu,Nd):YAl_(3)(BO_(3))_(4)(YAB)crystal codoped with Lu^(3+)and Nd^(3+)ions is described.The lattice parameters,spectral properties and laser performances of the VC(Lu,Nd):YAB and single-doped Nd:YAB(NYAB)crystals are measured and compared.The results indicate that the laser performances of NYAB crystal can be greatly improved by the VC doping.
文摘GaP nanocrystals were synthesized by both the organic solvent reflux and high temperature high pressure benzene thermal synthesis methods.The effect of organic solvent on the optical absorption properties of GaP nanocrystals were studied.The results show that crystal grains of the sample synthesized by the latter method have better quality and uniformity.The solvents which consist of polar molecules and form strong chemical bonds with Ga atoms cause obvious redshift of the absorption spectra of GaP nanocrystals.The absorption spectra redshift much more if the solvent molecules have π electrons which involved in the formation of complex bond between Ga atoms and solvent molecules.
文摘Cd_(x)(Sr_(0.61)Ba_(0.39))_(1-x)Nb_(2)O_(6)(CdSBN)crystals have been grown successfully by Czochralski technique.The difficulty in crystal growth increased with the increase of the crystal diameter.Macroscopic defects,such as striations and crackings were observed in some crystals.Temperature dependence of dielectric constant ε′γ3 and pyroelectric coefficient P were studied.The relationship between grown behavior and melt compositions was also discussed.
文摘Tb-doped SBN crystals were prepared by the Czochralski technique.Their dielectric,ferroelectric,and pyroelectric properties were studied.A low temperature phase transition between two polar phases was revealed by the anomalies of the dielectric and pyroelectric properties;the polar axis changes its direction during this transition.The point group of the low temperature phase may be mm2,m or 1.
文摘Two coherent or incoherent stable self-pumped phase conjugations have been obtained simultaneously in a Ce-doped(K_(0.5)Na_(0.5))_(2y)(Sr_(0.61)Ba_(0.39))_(1-y) Nb_(2)O_(6)(KNSBN)crystal by using two mutually coherent input beams from a He-Ne laser,and energy translation from one beam to another induces self-pumped phase conjugative reflectivity of one beam above 100%.
文摘The Cu-doped'KNSBN crystals have been grown.The self-pumped phase conjugate mirrors of Cu-doped KNSBN crystals have been demonstrated.The phase conjugate reflectivity reaches as high as 68% for the crystal with 0.04 wt.%Cu-doped.The phase conjugate reflectivity and its response time were also measured as a function of the argon-ion laser wavelengths.
文摘Striation-free LiBa_(2)Nb_(5)O_(15)(LBN)single crystal of good optical quality has been grown by Czochralski method.The crystal growth and dielectric,structural,spectral properties of LBN were measured.Experimental results show that LBN single crystal belongs to tetragonal tungsten bronze structure at room temperature.Experiments carried out with LBN powder samples have shown that this crystal has good second harmonic generation effect.At room temperature,the dielectric constant ε_(33) is about 87 and Curie temperature T_(c),is about 586℃.A very ideal uniaxial conoscope image can be observed in LBN single crystal under polarizing microscope.In the range of 600 to 2600nm,the transmission of single crystal is about 75%.
文摘This paper reports the growth of pqre and Na,K modified lead barium niobate crystals and the measurement of their dielectric and structure properties.Exprimental results show that both pure and Na,K modified lead barium niobate crystals have growth striations.All the crystals belong to 4mm point group of tetragonal system at room temperature.Their Curie temperature are 379℃,389℃ and 473℃,respectively.
基金Supported by a grant for Key Research Projection Climbing Program from the State Science and Technology Commission of China。
文摘In this paper,by comparing the three possible combinations of the basic structure unit TiO_(6) octahedra,a simple model is proposed to explain the cause of the formation of the bicrystal structure in KTiOPO_(4)(KTP)crystals.The theoretical morphology of KTP crystal is studied and the rate of the appearance possibilities of different faces are obtained.The relationships between bicrystal structure and crystal properties are discussed.
文摘Using dye laser as pumping light source,we have first realized on NYAB crystal the laser self-frequency doubling run from 1.06μm to 0.53μm.The threshold energy is less than 4mJ;conversion efficiency is 6.2%,and the self-frequency-doubling green light output energy is 2.5mJ.
文摘Potasium sodium lead barium niobate KNPBN crystals have been grown successfully by flux method.The dielectric constant along the polar axis was measured at 50 kHz as a function of temperature in the range of 0 to 400℃.The flux system,diffuse phase transition and optical absorption were also discussed.
基金Supported by the National Center for Research and Development on SuperconductivityInstitute of Crystal Material of Shandong University.
文摘Susceptibility measurements on Bi_(2)Sr_(2)CaCu_(2)O_(8) single crystals do reveal field-induced-suppression of sharp phase transition.No apparent anisotropy of the susceptibility was observed when magnetic field was applied along the three main directions a,b and c.The three dimensional isotropic fluctuation diamagnetism theory is proposed to explain our experimental finding of isotropic susceptibility.In a wide range of magnetic field,the temperature dependence of susceptibility does not show any obvious change in its character when the sample enters into expected vortex-lattice state from vortex-liquid state.
文摘A potassium lithium niobate crystal with tetragonal tungsten bronze structure was prepared by the Czochralski technique.The dielectric and pyroelectric properties were investigated in the temperature range of 300 to 10 K.A broadened ferroelectric-ferroelectric transition between phases with space group 4mm and space group m was found at about 80K.
基金Supported by the National Natural Science Foundation of China。
文摘By flux method,potassium tantalate niobate crystals with 46%Nb contents were prepared.In this material 90°a-type domains with(011)and(01ī)walls were observed by a transmission electron microscope,and the nature of fringe patterns associated with these domain walls was analysed.According to the extinction rules for the domain walls,the displacement vector R along<01ī>direction can be determined.Finally,using a selected area electron diffraction method,we examined the crystallographic character of these 90°domains and defined the ratio of lattice parameters c to a.