最新刊期
卷 14 ， 期 3 ， 1993
- 摘要：The luminescencc properties of Eu3+ in MFX series were studied systematically. Particular attention was paid to the affection of X-, M2+ and impurity defects(maily O2-) to the Eu3+ luminesconce.关键词：alkline earth fluohalides;Eu3+;fluorescence spectra124|76|0更新时间：2020-08-11
- 摘要：Zn1-xCdxSe multilayers structure have been grown on GaAs substrate by atmospheric pressure MOCVD. This multilayers structure was diagnosed as multiple quantum wells (MQWs) by X-ray diffraction rocking curve and photolumineseence. Free exciton absorption peak in this MQWs structure is observed in the transmitted spectrum at room temperature. We first found out the optical bistability in Zn1-xCdxSe-ZnSe MQWs with the nanosecond response time at room temperature.关键词：MOCVD;multiple quantum wells;ZnCdSe-ZnSe;optical bistability94|52|0更新时间：2020-08-11
- 摘要：In ordinary time delayed four wave mixing with incoherent light, the forward, backward pump and probe beams are from one source. In phase conjugation configuration, signal Is(τ) is from two dynamic gratings formed by interference of probe beam with forward or backward pump beams respectively. The complicity of the relation betwean Is(τ) and dephasing and depopulation times makes fitting error large.We propose in this paper a two source method, where backward pump beam is from a source independent of the one for forward pump and probe beams. In this case only one dynamic grating may be formed in the medium.关键词：incoherent light;time delayed four wave mixing;depopulation time;dephasing time98|62|0更新时间：2020-08-11
- 摘要：In this paper we propose a new method, which allows us to extract the carrier recombination time, diffusion coefficient and the decay time of the grating from the experimental results.According to the theory of laser-induced dynamic gratings and the phase-matching condition, we have obtained equations (7)-(10). So the decay time of grating, the carrier recombination time and the diffusion coefficient can be derived from relative intensities of the constant background and the two peaks around τ=0 and τ=-T in TDFWM-IL.Using the second harmonic of a Q-Swithed NdsYAG laser with τe=28 ps, seting T=230ps and θ=7.5°, we have measured Is(τ) for TiO2 ultrafine particles in the organosols as shown in Fig. 3. The intensity of the τ=-T peak is much weaker than that of the τ=0 peak. This phenomenon can not be attributed to carrier diffusion because the size of the ultrafine particle is much smaller than the period of the two gratings, carriers are effectively confined in the particles. We attribute I, (-T)/I,(0)<1 to the Brownian movement, which delocalize the excited particle makes the small period grating suffer more serious deterioration than the large period one. By Eq. (7)-(10) we have got T11=1.07ns, T12=0.56ns, TR=1.08ns, and D=0.016cm2/s. In Fig. 3,the two peaks are symmetric about τ=0 and τ=-T, respectively, with a constant background and separated by T=230 ps, just as the theory predicted.关键词：carrier recombination time;decay time of grating;diffusion coefficient;time-delayed four-wave mixing with incoherent light91|56|1更新时间：2020-08-11
- 摘要：The evident nonlinear optical absorption of CdS crystal at room temperature has been shown. In this paper, the conductivity of CdS crystal under intense excitation was measured, and the results were analyzed numberically based on the electron-exciton scattering model. The fact that theoretical results are in agreement with the experimental results denotes that the nonlinearity of CdS crystal can be attributed to the electron-exciton scattering.106|91|0更新时间：2020-08-11
- 摘要：The optical gain of CdSSe-doped glass (JB 510, made in China) was measured using Amplified Spontaneous Emission technique (ASE). At λ=625 nm, the optical gain is about 8 cm-1. The wavelength range where the optical gain, is present corresponds to the broad luminescence band due to the trap levels recombination. By measuring the trap luminescence decay time, a simple three-level model was used to interpret the occu-ring of the optical gain.关键词：CdSSe-doped glass;optical gain93|80|1更新时间：2020-08-11
- 摘要：Multi-layered Pd/Zn/Pd metallic films to form good ohmic contacts with p-type GaP have been reported.From the analysis of Auger electron spectroscopy(AES), it is concluded that, at 550℃ for 3min, tho optimum alloying process,P and Ga atoms move to metal layers from GaP surface, Pd atoms diffuse into interface layer,and Zn atoms diffuse into GsP substrate as well as out layer. Jn alloying process. Pd is found to play an important role in forming ohmic contact for Zn to be doped into GaP. Pd reacts with Ga and provides good wetting for Zn to adhere to the surface of GaP and the Ga sites are occupied by Zn, Zn atoms are acceptors when they occupy Ga sites in GaP and increase the carrier concentrations in GaP to form a high concentration p++ layer. So the contact interface has M-p++-p structure and the ohmic contact resistance is greatly lowered.From analysis of secondary ion mass spectroscopy (SIMS) combined with X-ray diffraction(XRD)measurments it is concluded that there are ZnP+, GaP+, ZnP2+, PdP+, Gat and PdZn+ ions in contact interface. The metallurgical phases of these complex ions are ZnP2, GaP, Zn3P2, Pd8P and(Ga4Pd7Zn3)14k in metal-semiconductor(M-S)contact layer. As a result, the M-S contact area is increased and the ohmic contact resistance for Pd/Zn/Pd structure system to p-type GaP is decreased.关键词：Pd-basod ohmic contacts for p-type GaP;Auger electron spectroscopy;secondary ion mass spectroscopy100|87|0更新时间：2020-08-11
- 摘要：There is a weak bulk coupling but a strong surface coupling between the electrons and phonon for many polar crystals. In this paper, the influence of the electron interaction with both the weak coupling bulk longitudinal optical (LO) and the strong coupling surface optical (SO) phonons on the temperature characteristic of the surface polaron is discussed. The temperature dependences of the vibration frequency, the induced potential and the effective mass of the surface polaron are investigated by using a linear-combination-operator method. Numerical calculation, for AgBr crystal as an example, illustrates that the vibration frequency, the induced potential and the effective mass of surface polaron will decrease with increasing temperature.122|112|4更新时间：2020-08-11
- 摘要：Using CaCO3, Mg(NO3)2·6H2O, CaCl2, SiO2 and Eu2O3 as raw materials, a new Eu2+-doped phosphor Ca8-xMg(SiO4)4Cl2:Eu2+ has been synthesized by high temperature solid phase reaction. Its crystal structure and fluorescence spectra show that the phosphor has single luminescent center and Eu2+ ion mainly occupies the site CaⅡ with the symmetry C2.106|70|2更新时间：2020-08-11
-
THE PHYSICAL PICTURE OF OPTICAL PARAMETRIC OSCILLATION PROCESS AND BBO OPTICAL PARAMETRIC OSCILLATOR
摘要：In this paper we used the ellipsoidal face of refractive index to describe the physical picture of the optical parametric oscillation process. The phase matching picture of the optical parametric oscillation and the simply mathematical formula of frequency tuning have been obtained. The frequency tuning behavior of the optical parametric oscillator was illustrated audiovisually and tersely by the formula and the face of refractive index. Using both 1.06 μm and 0.532μm laser to pump BBO crystal we have obtained the tuning ranges of 1.7-2.35 μm and 0.72-2.1 μm of BBO optical parametric oscillator. The conversion efficiency of energy is about 15%. The relationship of the output energy to cavity length was discussed in the angular tuning optical parametric oscillator.关键词：physical picture;optical parametric oscillation process;BBO crystal120|86|0更新时间：2020-08-11 - 摘要：The samples of La2Sn2O7:Ce3+,Tb3+ have been prepared by citric acid comploxing method. The crystal structure of samples was determined by X-ray powder diffraction.Luminoscent character and behavior of samples wore studied by excitation and emission spectra. Energy transmission and sensitization of Ce3+→Tb3+ were searched.117|64|0更新时间：2020-08-11
- 摘要：A new series of compounds La2Sn2O7:Bi3+ was synthesied by co-precipitation method for the first time. The crystal structure of samples was determined by X-ray diffraction. The behavior of Bi in luminophor were studied with excitation and emission spectra.关键词：co-precipitation method;luminescent behavior;lumino-phor120|85|0更新时间：2020-08-11
- 摘要：Dysprosium-Yttrium-benzoate solid complexes, (Dy1-xYx)L3, have been synthesized with homophase precipitation method in aqueous solution. Their luminescence properties and the influence of concentration of Y3+ ions added on luminescence intensity of the complexes were studied. According to the IR absorption spectra of (Dy1-xYx)L3 and the results investigated by Taylor to the structure of anhydrous rare earth ben-zoates, the supposed coordination structure for the complexes is as followThe emission spectra of EuL3, DyL3 and (Dy1-xYx)L3 show that Dy3+ ion in rare earth benzoate occupies the similar site of Eu3+ ion which is not a centre of symmetry in benzoate.Because the occurrence of concentration quenching with higher concentration of Dy3+ ions, the f→f transition for Dy3+ ion in pure DyL3 is very weak. It was found in experiments that if Y3+ ions as a reactent were added in synthetic process of DyL3, the luminescence intensity of Dy3+ ions could be substantialy enhanced and was obtained with satisfactory result when the substitution of 85 mole% Dy3+ for Y3+ ions. The energy transfer between benzoic group and Dy3+ ion through the excitation and emission spectra of NH4L and complexes the absorption spectra of DyL3, as well as the quenching of TTA to the Dy3+ ions emission were observed.The luminescence of physical mixture of DyL3 with YL3 in any propotion is weaker than the pure DyL3. Only the doped Y3+ ions in a way of common precipitation can raise the omission intensity of Dy3+ ions. From this fact, it may be supposed that (Dy1-xYx)L3 is a kind of solid solution, besides the dilution to Dy3+ ions, and the YL3 "should play a role of intermolecular transfer of energy in the complexes. The Y/B ratio of Dy3+ ions in aqueous complexes is greater than that in anhydrous complexes.The Y/B ratio of Dy3+ ions in anhydrous complexes is not changed with the change of the concentration of Dy3+ ions.关键词：dysprosium benzoate;yttrium benzoate;rare earth complexes;luminescence116|73|10更新时间：2020-08-11
- 摘要：Ⅴ.orientalis 518 strain was cultured in liquid medium, with shaking at 20℃ for 16 hours. Cells were harvested at the late log phase by cen-trifugation and lysed by addition of cold distilled water to the cell paste. Then, it Was treated with ultrasonic in an ice bath.The rough luciferase was isolated from the above suspension of cells. Then it was purified by DEAE-Cellulose chromatography as well as DEAE-sephadex chromatograhy. By means of sephadex G-100 gel filtration, it has been determined that the molecular weight of this luciferase is 87000 and by means of SDS-PAGE it has been determined that there are two subunits αand β in luciferase and their molecular weight are 44000 and 41000 respectively.The reaction system contains the compounds with the following concentration: 5.1μuM FMN, 3.4mM sodium dithionite, 2.2μM catalase, 1.9 mM decanal and 85mM H2O2. Some properties of the luciferase were studied. The maximun luciferase activity was obtained at 18℃, pH 6.8. The luciferase was sensitive to heat treatment. It lost its catalititc activity at above 25℃. The results showed that the luciferase lost above 95% of its activities after pre-treatment at 40℃ for 40 minutes.The luciferase had a luminescent peak at 490nm. It was consistent with previous reports.关键词：luminescent bacteria;bacterial luciferase;Vibrio orientalis109|65|2更新时间：2020-08-11
- 摘要：Nonlinear optical properties of semiconductor microcrystalline are reviewed. A novel growth technique enabling to obtain semiconductor micro-crystalline with controlled size grown in a porous glass matrix is described. And the split of the energy level is observed. The quantum dots of Rh6G and RhB embedded in the porous glass are also obtained by absorption of the dye solutions on porous glass.The blue-shift of the pho-toluminescence peak can be observed.123|92|0更新时间：2020-08-11
- 摘要：A high pressure optical diamond anvil cell used under 300-20 K low temperature and its correlative micro-spectral system have been set up. A characteristic of this diamond anvil cell is that it can be increased its pressure under low temperature.110|69|1更新时间：2020-08-11
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