We observed the photorefractive spatial dark-soliton stripes In LiNbO3:Fe crystal,and demonsirate the planar waveguide property of refractive index proiile induced by these spatial dark-soli ton stripes.We suggest a n...We observed the photorefractive spatial dark-soliton stripes In LiNbO3:Fe crystal,and demonsirate the planar waveguide property of refractive index proiile induced by these spatial dark-soli ton stripes.We suggest a new mothed to form the planar waveguide utilizing the grating fixing technique.展开更多
The domain reversal characteristics of near-stoichiometric LiNbO3 ([Li]/[Li+Nb]=0.496) single crystals, which are grown by the Czochralski method with K2O tlux, are investigated. The switch tield for 180° ferroel...The domain reversal characteristics of near-stoichiometric LiNbO3 ([Li]/[Li+Nb]=0.496) single crystals, which are grown by the Czochralski method with K2O tlux, are investigated. The switch tield for 180° ferroelectric domain reversal in the near-stoichiometric LiNbO3 crystal is 8.0±0.5kV/mm, which is only one third of the switching field required for the congruent LiNbO3 crystals. We have successfully achieved 180° domain reversal in near-stoichiometric LiNbO3 samples of 1.0mm thickness.展开更多
A new method to suppress the fanning noise caused by He-Ne laser in the cooperation with Ar+laser in photorefractive LiNbO_(3):Fe crystal was successfully realized.This method is simple and efficient.By using this met...A new method to suppress the fanning noise caused by He-Ne laser in the cooperation with Ar+laser in photorefractive LiNbO_(3):Fe crystal was successfully realized.This method is simple and efficient.By using this method,fanning-noise-free hologram can be stored in LiNbO_(3):Fecrystal.展开更多
Light-induced absorption in the nominally pure bismuth silicon oxide is investigated experimentally and the result shows that it consists of transient and persistent parts. The experimental evidence is analysed based ...Light-induced absorption in the nominally pure bismuth silicon oxide is investigated experimentally and the result shows that it consists of transient and persistent parts. The experimental evidence is analysed based on the model of three groups of trap (donor) centres.展开更多
The typical laser characteristics of a laser diode pumped,solid-state laser with a Z-type resonator structure are analyzed by the transform circle approach.Laser waists change with the thennal focus length of the lasi...The typical laser characteristics of a laser diode pumped,solid-state laser with a Z-type resonator structure are analyzed by the transform circle approach.Laser waists change with the thennal focus length of the lasing medium so that the output power becomes unstable.In particular,there is a very unstable operation region when the pump power is of medium magnitude.A method is put forward to avoid this situation.展开更多
For a photorefractive crystal,the exponential gain coefficient of two-wave coupling,Г,is a constant.In this paper,the constantГof a LiNbO_(3):Fe crystal is measured by using Gaussian beams and quasi-uniform beams.Th...For a photorefractive crystal,the exponential gain coefficient of two-wave coupling,Г,is a constant.In this paper,the constantГof a LiNbO_(3):Fe crystal is measured by using Gaussian beams and quasi-uniform beams.The difference between the results is attributed to the self-defocusing effect of the crystal.展开更多
We analyze the valence and electronic shell configuration characters of all damage-resistant dopants found in LiNbO_(3) crystals up to now.We show that all damage-resistant dopants have only one valence state.We also ...We analyze the valence and electronic shell configuration characters of all damage-resistant dopants found in LiNbO_(3) crystals up to now.We show that all damage-resistant dopants have only one valence state.We also show that the electronic shell configurations of these damage-resistant ions are filled fully,as are the cases of the inert elements.from this point of view,we conclude that the anti-site NbLi should be involved in the charge transport process,while the Li vacancy VLi is not involved in the charge transport process.It also can give us some insights about how to select a damage-resistant dopant for LiNbO_(3) crystal.展开更多
In this paper,the modulated transmission property of bacteriorhodopsin(bR)film is analyzed theoretically when two beams of light,yellow light and purple light,illuminate the bR film simultaneously.By using the transmi...In this paper,the modulated transmission property of bacteriorhodopsin(bR)film is analyzed theoretically when two beams of light,yellow light and purple light,illuminate the bR film simultaneously.By using the transmission property of bR film,the winner-take-all thresholding operation can be realized.展开更多
Experimental studies of light amplification with dynamic multiwave gratings recorded in an acceptor-donor-substituted azobenzene-doped poly(methyl methacrylate)thin film by multi-wave mixing are reported.The amplifica...Experimental studies of light amplification with dynamic multiwave gratings recorded in an acceptor-donor-substituted azobenzene-doped poly(methyl methacrylate)thin film by multi-wave mixing are reported.The amplification gain was measured to be as high as 6.7,and the operation at red light wavelength decreases the absorption losses.展开更多
A self-excitation double pathway relaxation oscillation mechanism to deal with the seif-pulsing output of up conversion laser with rare-earth ions as the active material is raised.The reabsorption of the laser signal,...A self-excitation double pathway relaxation oscillation mechanism to deal with the seif-pulsing output of up conversion laser with rare-earth ions as the active material is raised.The reabsorption of the laser signal,which causes self-excitation of system and two-pathway transition of systepi,plays a role of adjusting Q,and causes the oscillation output of laser.A qualitative analysis to the appearance of self-pulsing output of rare-earth-doped laser is given.展开更多
The effects of electron-phonon interaction have to be taken into account for the physical process in a small system of condensed matters.The electron-phonon interaction in a I-D finite lattice system has been analyzed...The effects of electron-phonon interaction have to be taken into account for the physical process in a small system of condensed matters.The electron-phonon interaction in a I-D finite lattice system has been analyzed.The relation between the electron-phonon interaction and the symmetric properties of electronic states and phonons are considered,the transition probabilities are discussed.展开更多
We have observed the granular deposition of metallic Li on theα-LiIO_(3) surface in contact with the cathode of DC field by a scanning electron microscope.The relationship between the accumulation lines of space char...We have observed the granular deposition of metallic Li on theα-LiIO_(3) surface in contact with the cathode of DC field by a scanning electron microscope.The relationship between the accumulation lines of space charges und the ionic transportation along c-axis is discussed.展开更多
基金Supported by the Third World Academy of Sciencesthe National Natural Science Foundation of Cliinathe Key Research Project in Climbing Program from the State Science and Technology Commission of China.
文摘We observed the photorefractive spatial dark-soliton stripes In LiNbO3:Fe crystal,and demonsirate the planar waveguide property of refractive index proiile induced by these spatial dark-soli ton stripes.We suggest a new mothed to form the planar waveguide utilizing the grating fixing technique.
基金Supported by the National Advanced Material Committee(grant 863-715-001-0102)and special funding for the excellent young researchers from the National Natural Science Foundation of China under Grant No.69825108and National Education Ministry of China,“973”Project(grant 1999033004).
文摘The domain reversal characteristics of near-stoichiometric LiNbO3 ([Li]/[Li+Nb]=0.496) single crystals, which are grown by the Czochralski method with K2O tlux, are investigated. The switch tield for 180° ferroelectric domain reversal in the near-stoichiometric LiNbO3 crystal is 8.0±0.5kV/mm, which is only one third of the switching field required for the congruent LiNbO3 crystals. We have successfully achieved 180° domain reversal in near-stoichiometric LiNbO3 samples of 1.0mm thickness.
基金Supported by the National Natural Science Foundation of China,and the National Climbing Programme of Fundamental Research。
文摘A new method to suppress the fanning noise caused by He-Ne laser in the cooperation with Ar+laser in photorefractive LiNbO_(3):Fe crystal was successfully realized.This method is simple and efficient.By using this method,fanning-noise-free hologram can be stored in LiNbO_(3):Fecrystal.
基金Supported by the Special Funds for Excellent Young Researchers from the National Natural Science Foundation of China under Grant Nos.69825108 and 19734040the National Education Ministry of China,and“973”project(Grant G1999033003).
文摘Light-induced absorption in the nominally pure bismuth silicon oxide is investigated experimentally and the result shows that it consists of transient and persistent parts. The experimental evidence is analysed based on the model of three groups of trap (donor) centres.
基金Supported by Tianjin Natural Science Foundation under Grant No.99380111the National Natural Science Foundation of China under Grant No.69825108。
文摘The typical laser characteristics of a laser diode pumped,solid-state laser with a Z-type resonator structure are analyzed by the transform circle approach.Laser waists change with the thennal focus length of the lasing medium so that the output power becomes unstable.In particular,there is a very unstable operation region when the pump power is of medium magnitude.A method is put forward to avoid this situation.
基金Supported by the National Natural Science Foundation of China under Grant Nos.69678018 and 19734004the Key Research Project in Climbing Program from the National Science and Technology Commission of Chinathe National Advanced Materials Committee of China.
文摘For a photorefractive crystal,the exponential gain coefficient of two-wave coupling,Г,is a constant.In this paper,the constantГof a LiNbO_(3):Fe crystal is measured by using Gaussian beams and quasi-uniform beams.The difference between the results is attributed to the self-defocusing effect of the crystal.
基金Supported by the National Natural Science Foundation of China under Grant Nos.69678018 and 19734004the Key Research Project in Climbing Program from the State Science and Technology Commission of Chinathe National Advanced Materials Committee of China.
文摘We analyze the valence and electronic shell configuration characters of all damage-resistant dopants found in LiNbO_(3) crystals up to now.We show that all damage-resistant dopants have only one valence state.We also show that the electronic shell configurations of these damage-resistant ions are filled fully,as are the cases of the inert elements.from this point of view,we conclude that the anti-site NbLi should be involved in the charge transport process,while the Li vacancy VLi is not involved in the charge transport process.It also can give us some insights about how to select a damage-resistant dopant for LiNbO_(3) crystal.
基金Supported by the National Natural Science Foundation of China under Grant No.19674030the Tianjin Natural Science Foundation,and W.M.Keck Foundation in Syracuse University.
文摘In this paper,the modulated transmission property of bacteriorhodopsin(bR)film is analyzed theoretically when two beams of light,yellow light and purple light,illuminate the bR film simultaneously.By using the transmission property of bR film,the winner-take-all thresholding operation can be realized.
基金Supported by the National Natural Science Foundation of China under Grant No.69477008Tianjin Science and Technology Foundation For Youth under Grant No.953700911.
文摘Experimental studies of light amplification with dynamic multiwave gratings recorded in an acceptor-donor-substituted azobenzene-doped poly(methyl methacrylate)thin film by multi-wave mixing are reported.The amplification gain was measured to be as high as 6.7,and the operation at red light wavelength decreases the absorption losses.
文摘A self-excitation double pathway relaxation oscillation mechanism to deal with the seif-pulsing output of up conversion laser with rare-earth ions as the active material is raised.The reabsorption of the laser signal,which causes self-excitation of system and two-pathway transition of systepi,plays a role of adjusting Q,and causes the oscillation output of laser.A qualitative analysis to the appearance of self-pulsing output of rare-earth-doped laser is given.
文摘The effects of electron-phonon interaction have to be taken into account for the physical process in a small system of condensed matters.The electron-phonon interaction in a I-D finite lattice system has been analyzed.The relation between the electron-phonon interaction and the symmetric properties of electronic states and phonons are considered,the transition probabilities are discussed.
文摘We have observed the granular deposition of metallic Li on theα-LiIO_(3) surface in contact with the cathode of DC field by a scanning electron microscope.The relationship between the accumulation lines of space charges und the ionic transportation along c-axis is discussed.
