最新刊期
卷 18 ， 期 3 ， 1997
- 摘要：The emission spectra of LiYF4:Eu under high pressure up to 15GPa have been measured at room temperature. On the basis of the spectra the dependence of the stark levels of 5D0,1 and 7F1-4 multiplets on pressure have been investigated. An obvious change in the spectra occurred and some spectral lines split into two at pressure range from 10.0 to 10.5GPa. This phenomenon shows that a structure phase transition occurred in LiYF4:Eu and the crystal symmetry lowered at the pressure range.关键词：emission spectrum;high pressure;LiYF4：Eu;phase transition90|79|0更新时间：2020-08-11
- 摘要：By high temperature solid state reaction, CaAl3BO7:RE was synthesized at 1140℃. The luminescent properties of Ce3+, Gd3+, Tb3+ and sensitization of Ce3+ to Tb3+ have been studied. The excitation band peaking at about 340nm and the broad emission band maximizing around 400 nm of the Ce3+ are due to 4f-5f allowed transition. The emission feature of the Ce3+ indicates that there is the stronger crystal field at the surroundings of the Ce3+ ion, leading to the extensive crystal field splitting of 4f ground state. The absence of energy transfer of Ce3+-Gd3+-Tb3+ is due to the fact that 5d state of Ce3+ is lower than 6I and 6P states of the Gd3+. Energy transfer from Ce3+ to Tb3+ in the CaAl3BO7 is efficient.关键词：CaAl3BO7：RE;luminescence of rare earth ion;energy transfer125|79|1更新时间：2020-08-11
- 摘要：The signal intensity of quantum beats to V-level atomic system has deduced by density matrix equation and the result has analysized and discussed in present paper.关键词：V-level system;quantum beats;quantum coherent effect91|87|1更新时间：2020-08-11
- 摘要：Photoluminescence of shallow Zn0.92Cd0.08Se/ZnSe single quantum well grown by LP MOCVD was measured for different excitation intensity at 77K. The spontaneous spectra show two emission peaks at 451.5nm and 452.9nm respectively. Compared to stimulated emission spectra, we can see that the stimulated emission came from the high energy emission peak in spontaneous emission spectra. The origin of the stimulated emission was attributed to exciton exciton process in the sample.关键词：shallow ZnCdSe/ZnSe MQWs;photoexcite;stimulated emission105|106|0更新时间：2020-08-11
- 摘要：Undoped bulk InP was grown along <100> direction by the liquid-encapsulated vertical Bridgman (LE-VB) technique. Photoluminescence spectra of as-grown InP at 4.2K were consisted of three parts. A peak exhibited near band gap energy is attributed to the recombination of bound excitons. At the low energy side of bound exciton (BE), a series of peaks with same energy interval are due to the recombination of donor-acceptor (DA) pairs with their phonon replicas, which are associated with Zn acceptor. A deep level recombination is characterized by a series of resolvable peak at its higher energy side, which can be associated with emission of native defects and their phonon replicas. The comparison results of the 4.2K PL spectra showed that in LE-VB crystsl the lattice relaxations of the DA emission are smaller and the PL intensities of the DL are stronger than those in the seed crystal grown by liquid-encapsulated czochralski (LEC)technique. At room temperature, only a band-to-band recombination was observable in both as-grown LE-VB crystal and LEC seed crystal. The PL mapping results showed that PL intensities of the band-to-band recombination in LE-VB crystal are stronger than those in LEC crystal. By combining the Huber etch pit density analysis, it is considered that the stronger PL intensities of the band-to-band recombination in LE-VB crystal can be due to the lower densities of the native defects responsible for the DL recombination and of the dislocations responsible for the Huber etch pit. The densities of the native defects and dislocations in the crystal can be reduced by LE-VB technique.关键词：compound semiconductor;photoluminescence;crystal growth107|68|0更新时间：2020-08-11
- 摘要：The diode-laser end-pumped microchip crystal laser is presented in this paper. A novel structure of the all solid-state laser is designed. The microchip Nd:VO4 crystal is used as a laser medium, and its thickness is 1mm. The LD at wave-length of 809nm is used as a pump source. It is emphasized that a unique optical coupling system is designed. This system consits of both the coupling system and the focusing system for the LD laser beam. In order to achieve high conversion efficiency and increase the output power, the hemiconfocal resonator is chosen. The resonator is a combination of one of Nd:VO4 crystal plane surfaces and spherical mirror of the radius of curvature R=21mm, and the resonator's length is 10.5mm. The mode matching between the pump beam and laser mode in the active material is discussed in detail for single transverse mode operation. The output power of 152mW of TEM00 mode at 1064nm has been obtained for pumping power of 400mW. The correspondig laser threshold is 48.3mW. The total optical to optical conversion efficiency and slope efficiency are 38% and 43%, respectively.关键词：LD;pumped;microchip Nd:VO4;laser113|74|1更新时间：2020-08-11
- 摘要：The deposition rate and refractive index for SiO2 and a-Si by PECVD were studied under different conditions. a-Si/SiO2 MQW (multi-quantum well) with high quality were deposited under suitable conditions. It was crystallized by laser annealing and silicon crystalline grain was formed. The grains of Si with size of 3.8nm was found if a-Si layer in the MQW structure was 4nm. Strong photoluminescence with three peaks from the grains was detected at 10K. The wavelengths of the peaks were 810nm, 825nm and 845nm, respectively.关键词：PECVD;a-Si/SiO2 MQW;crystallization;photoluminescence98|48|6更新时间：2020-08-11
- 摘要：InAs epilayers and InAs/GaSb heterostructure were grown by atmospheric pressure metalorganic chemical vapor deposition(MOCVD) on GaSb and GaAs substrates with trimethylindium, trimethylgallium, trimethylantimony and arsine as precursors at lower Ⅴ/Ⅲ ratio(1.5～4). The growth efficiency for Ⅲ group precursors equal to 3×103μm/mol. Experimental results indicated that the growth of InAs was controlled by diffusion for growth temperature tg in 500℃～600℃ range. The undoped InAs epilayer is n type and its mobility at room temperature is 2000cm2/V.s. The PL spectra of InAs/GaSb heterostructure at 12K includes a wider peak at 375meV corresponding to emission processes involving with impurity and defects states and a weak band-edge peak at 417meV.关键词：InAs;MOCVD;heterostructure118|84|1更新时间：2020-08-11
- 摘要：Multilayer InAs quantum dots (QD) have been grown by MBE on (001) GaAs substrates. TEM observation shows several vertical aligned InAs dot columns. Compared with single InAs QD layer structure, the red shift of the PL wavelength is found for multilayer InAs QD layer structure, which indicate the coupling effect in quantum dots located in the columns. The anomalous decrease of FWHM is attributed to the carrier tunneling between nearby columns.关键词：quantum dots;MBE;photoluminescence100|61|1更新时间：2020-08-11
- 摘要：In this paper, reported is the experimental results of the electroinduced second order non-linear polarization in fused silica and its thermal erasure. By means of the measurement of electroinduced second harmonic generation, it is found that the second order nonlinear polarization in fused silica not only increases with the poling time and reaches saturation gradually when the poling condition is fixed, but also can be erased by means of heat treatment and decreases with erasing time. The results is discussed according to the dipole orientation model for the electroinduced second order nonlinear polarization in glasses.关键词：fused silica;electroinduced second harmonic generation;thermal erasure;dipole orientation95|69|0更新时间：2020-08-11
- 摘要：The integrated optics wavelength division multiplexing device using geodesic lens and grating has been fabricated. The principle and fabricating technology of the wavelength division multiplexing device are discribed in this paper. The design and measurement of the optical characteristics for key component in the device the waveguide grating and the spheroidal geodesic lenses are discribed, the experimental results of the wavelength division characteristics are reported in the paper.关键词：geodesic lens;waveguide grating;wavelength division multiplexing device101|75|1更新时间：2020-08-11
- 摘要：In PyTS and MV2+ mixture solution in water, the PyTS/MV2+ complex can be formed by electrostate interaction between PyTS and MV2+. From absorption titration results, the stoichiometry of PyTS/MV2+ complex is 1:1 dimer. However, the stoichiometries in PyTS/MV2+ complex have 1:1 dimer and 1:2 trimer from fluorescence titration results, these results indicate that fluorescence titration method is more sensitive than absorption titration. The transient absorption peaks of MV + and PyTS + have been detected using nanosecond transient absorption method, it shows that the electron transfer process from PyTS to MV2+ occurs when the PyTS/MV2+ complex was excited. We proposed the dynamic schemes from fit results of absorption decays.关键词：PyTS/MV2+ complex;stoichiometry;transient absorption spectrum;dynamic schemes126|64|0更新时间：2020-08-11
- 摘要：Chitosan, for which ligands within each structural unit can be used as a filmy me dium to prepare the nanometer-sized clusters of CdS and ZnS by complex transformation method. The supermicroparticles have been obtained with controlled particle-size, uniform distribution of dimension and little crystalline imperfection on the surface.100|62|3更新时间：2020-08-11
- 摘要：Using chitosan, a process was developed to prepare nanocrystalline manganese-doped zinc sulfide by anion-coordination method. Chitosan that contains ligand groups acts not only as a polymer matrix but also as a surfactant. By the reaction of zinc acetate and manganese acetate mixture in chitosan film with sodium solution, particles sizes(4.0～7.0nm by caculation) were obtained by controling of reactant concentration, and managanese was successfully doped. The optical characteristics were observed by PLE and PL spectroscopy. The coordination of the chitosan to the nanoparticle surface was investigated by FTIR spectroscopy.103|76|6更新时间：2020-08-11
- 摘要：Immunogen was testosterone-3-carboxymethyl oxime-bovine serum albumin(To-3-CMO-BSA), and tracer ligand was testosterone-3-carboxymethyl oxime-4-(10-methy)-acridinium-9-carboxylate(To-3-CMO-AEPMAC). A chemiluminescene immunoassay of testosterone(To-CLIA) was established, on the equilibrium method, by raising the antiserum in rabbits against To-3-CMO-BSA. The data was processed by the four-parameters logistic function program. The intra- and inter-assay CV of To-CLIA were 5.78% and 3.30%, respectively, the recovery rate, 107.28%. The antiserum provided a linear response from 19.3 to 264.6ng/L with ED 50 of 82.15ng/L and correlation coefficient of curve fitting, 0.9967. The cross reactivity with estrone, estradiol, estriol and progesterone were less 1.35%. Non-specific bound rate was 9.64%. The highest affinity constant could be obtained by "bridge effect" analysis with same structure of the "bridge" in the same position of testosterone.关键词：acridium ester;testosterone;chemiluminescene;immunoassay;parameter111|80|1更新时间：2020-08-11
- 摘要：The LED leading system for passengers is a system similar to network structure with one computer controlling several monolithic processors, and its control mode is flexible. With the LED, the display is visual, wonderful, flexible and durable. The control software offers a perfect user interface, which makes the operation simple and easy to grasp.关键词：LED;monolithic processor;bidirectional circular chain91|67|0更新时间：2020-08-11
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