Chinese Journal of Quantum Electronics
Co-Editors-in-Chief
Zhiben Gong
2002
Volume: 19 Issue 5
17 Article(s)
[in Chinese], and [in Chinese]

The principles and methods to magnetically guide cold neutral atoms using various current-carrying wires and permanent magnetic tubes and their recent, experimental progresses are reviewed, and some applications of atomic magnetic guiding techniques in atomic optics, Bose-Einstein condensation (BEC) experiment and the developments of atom optical devices are also introduced.

Oct. 01, 2002
  • Vol. 19 Issue 5 385 (2002)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    In this paper, the principle and the structure of micro-strip gas chamber (MSGC), which include the selection of the substrate materials, the strip materials and the operating gas, were reviewed. The future application of MDGCs, the limitation of their performances and the improvement were also discussed and reported.

    Oct. 01, 2002
  • Vol. 19 Issue 5 396 (2002)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Ultrafast spectroscopy in the light-harvesting complex II, photosystem II particle complex and photosytem II core complex has been studied using ICCD femtosecond image scanning set and femtosecond time resolved spectrometer. 7 spectral components of chlorophyll a/b molecule have been obtained from the trimeric light-harvesting complex II, and they areChl b653/656658.7、Chl a662.0665.2、Chl a/b670/671671.6、Chl a675.0677.1、Chl a680/681682.9、Chl a685.0689.1 and Chla695.0695.6(Chl aae, a is the absorption spectrum peak, e is the emission spectrum peak). Exciting in the trimeric light-harvesting complex at 440 nm with intensity of 1013 photos/cm2/pulse, fluorescence kinetics from 605 nm to 705 nm, yields 4 ultrafast component lifetimes of 210 fs and 520 fs, 5.2 ps and 36.7 ps, and 2 long component lifetimes of 1.8 ns and 2 ns. The three fastest lifetimes of 210 fs , 520 fs and 5.2 ps directly reflect from trimeric Chl b to Chl a energy transfer processes. The lifetime 36.7 ps shows the energy transfer time from Chl a to nearby monomer Chl a.The longest 2 lifetime reflect the energy transfer processes of Chl a molecules from excited state to ground state through middle Chl a molecules in the trimeric.CP43 and CP47 of PSII core antenna has three Chl a molecules of different condition ,they are CP43-Chla660661、Chla669670、Chla682686,CP47-Chla660661、Chla669670、Chla680681。

    Oct. 01, 2002
  • Vol. 19 Issue 5 404 (2002)
  • [in Chinese], and [in Chinese]

    An optically thin gaseous mixture of Cs and Na is excited by the CW dye laser, the laser frequency v is tuned in the wings of the Na resonance transitions. The excited NaCs molecule is predissociated into the Na3P1/2 or 3P3/2. The branching ratio is defined as 7(D1)/I(D2) where I(D1) and I(D2) are measured intensities of the atomic NaD1 and D2 lines. The branching is determined in the Cs density range 2 to 8 × 1014cm-3. The ratio is measured for detuning ranging from about 300 cm-1 in the blue wing to 100 cm-1 in the red wing of the Na3P multiplet. The ratio of dissociation rates and the fine structure changing cross section are obtained. The branching is found to be strongly detuning dependent in the vicinity of the NaCs near-wing satellites. Fine structure changing cross section has also been measured for resonant excitation of Na3~2PJ state. The results are discussed.

    Oct. 01, 2002
  • Vol. 19 Issue 5 410 (2002)
  • [in Chinese]

    The diffraction formula for an arbitrary wave by small aperture is used to calculate the intensity and power distribution for the diffraction pattern of some Gaussian beams by several annular apertures. The errors of the optical quality factor evaluated on the base of the diffraction by circular apertures are evaluated for optical systems with annular apertures. It is concluded that the wave type and aperture geometry have to be taken into account in evaluating the optical quality of an optical system.

    Oct. 01, 2002
  • Vol. 19 Issue 5 414 (2002)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Based on aberration theory, a way of designing beam expander with aspheric surface is introduced. Objective lens of beam expander with a high-order curved surface can correct aberration for a deep relative aperture lens. The tendency is that larger relative aperture, higher the high-order term of objective lens, more complicated the configuration of eyepiece and shorter the length of canister, An example is given here with good accordance to calculation.

    Oct. 01, 2002
  • Vol. 19 Issue 5 418 (2002)
  • [in Chinese], and [in Chinese]

    A group of six-temperature model rate equations for describing the kinetic process of tunable TE(A) CO2 lasers are given in this paper, which can be applied for studying the laser output characteristics of various tunable TE(A)CO~~2 lasers. Several calculating results are given as illustrations.

    Oct. 01, 2002
  • Vol. 19 Issue 5 425 (2002)
  • [in Chinese], and [in Chinese]

    For the first time, we have stimulated the SHG efficiency versus the polarization ratio and the crystal length of CLBO, which is pumped by the Q-switched Nd:YAG fundamental radiation with the wavelength of 1064nrn, with the shape of plane wave or the Gaussian beam, under the circumstance of phase matching. When the pumped radiation is of plane wave, the conversion efficiency of type-I and type-II SHG could be as high as 100% and 80%;when the pumped radiation is of Guassan beam, the correspondent efficiency could be 68.3% and 80%, respectively. It is necessary that the phase matching of type-II be utilized in the SHG of CLBO.

    Oct. 01, 2002
  • Vol. 19 Issue 5 431 (2002)
  • [in Chinese]

    The antibunching effects for the eigenstates of the Nth powers (N > 3) of the annihilation operator of the non-harmonic oscillator are studied. Using the numerical method, we have investigated the influences of the non-harmonic term on the effects under the circumstance of N=3. The results show that the antibunching effects for the eigenstates of the higher powers of annihilation operator of the non-harmonic oscillator are evidently different from those of the eigenstates of the harmonic oscillator. The effects can be shown in a number of intervals alternately when x = |β|2, which reflects the intensity of non-harmonic oscillator light field, is changed, and the intervals that the antibunching effects are exhibited are changed larger when the non-harmonic term is greater.

    Oct. 01, 2002
  • Vol. 19 Issue 5 435 (2002)
  • [in Chinese], [in Chinese], and [in Chinese]

    In this paper, the photon statistical evolution of two coupling atoms interacting with a single mode light field in a Kerr medium is studied by means of the quantum theory. The influences of the Kerr medium on the mean photon number is also discussed. The relations between the excited field intensity, the coupling constants of two atoms and the mean photon number are revealed.

    Oct. 01, 2002
  • Vol. 19 Issue 5 440 (2002)
  • [in Chinese]

    When an initial entangled state is transformed into a target entangled state by local operations and classical communication (LOCC), the quantity of entanglement of the initial state decreases. Morikoshi (reference [10]) showed that the entanglement lost in the transformation can be partially recovered by an auxiliary entangled state. However, the entanglement degree of the auxiliary entangled state is required to be larger than that of the target state. This paper shows that the entanglement catalysis can be used to assist the recovery of the entanglement even the entanglement degree of the auxiliary entangled state is less than that of the target state. Some necessary conditions for the entanglement catalysis are also given.

    Oct. 01, 2002
  • Vol. 19 Issue 5 446 (2002)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    According to linear superposition principle of quantum mechanics, it is constructed respectively two new type of multi-mode superposition state light field. By using the general theory of the unequal-order multi-mode squeezed state, the properties of generalized nonlinear second-order unequalled-power Aj-th power H-squeezing of the two type multi-mode superposition states mentioned above are studied firstly in detail. It is found that the two new type multi-mode superposition states can present second-order unequalled-power Nj-th power H-squeezing effect that changes periodically under the case of different amplitude power of each mode (the amplitude powers of all modes are even number;or the amplitude powers of all modes are odd number;or part modes are odd and others are even ), and the initial phase of each mode, and the two state superposition propability amplitudes, and all of the cavity-mode number and so on satisfy respectively certain condition. This pure quantization effect demonstrates that the two states are typical multi-mode nonclasical light fields,and found that between the states mentioned above present the phenomena of second-order unequal-power N~~j-th power H-similitude squeezing and N~~j-th power H-degenerate squeezing.

    Oct. 01, 2002
  • Vol. 19 Issue 5 450 (2002)
  • [in Chinese], [in Chinese], and [in Chinese]

    In this paper, the photocurrent self-correlation function of uniform-frequency crosstalk is discussed in arrayed waveguide grating, the self-correlation coefficient of uniform-frequency crosstalk is researched in theory. The relation of correlation coefficient and delay as uniform-frequency crosstalk, RF and τ、n, noise power of uniform-frequency crosstalk and polarization direction are investigated, the obtained conclusions numerical results demonstrate that the signal transmission of AWG exists negative correlation section, weakly correlation and positive correlation section. The effect of crosstalk delay vs enregistration is a periodicity chang.

    Oct. 01, 2002
  • Vol. 19 Issue 5 457 (2002)
  • [in Chinese], and [in Chinese]

    In this report, we have studied the effect of temperature-rising-rate on the sizes of nanoscale siliconparticles formed in thermally annealed hydrogenated amorphous silicon (a-Si:H) films. The a-Si:H films wereprepared with electron-beam evaporation in a high-vacuum chamber, then the films were thermally annealedin a furnace at the equilibrium temperature of 620℃ for about 10 seconds but with a high (~100 ℃/min) anda low (~1 ℃/min) temperature-rising-rate in the first stage of their thermal annealing processes, respectively.Using the micro-Raman scattering and the X-ray diffraction techniques, we have found that sizes of the formedsilicon particles change with the temperature-rising-rate in the process of thermal annealing the a-Si:H films.When the a-Si:H films have been annealed with high temperature-rising-rate (~100 ℃/s), the sizes of nanoscalesilicon particles are small in the range of 1.6~15 nm. In the meanwhile, if the a-Si:H films are annealed witha low temperature-rising-rate (~1℃/second), the sizes of nanoscale silicon particles are large in the range of23~46 nm. Using the method of diffusion limited aggregation, we have simulated the growth of nanoscale siliconparticles in a-Si:H films and discussed the effect of temperature-rising-rate on the sizes of the formed siliconparticles.

    Oct. 01, 2002
  • Vol. 19 Issue 5 461 (2002)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Nd:YAG continuous laser was used to irradiate the n-InP substrates which wore vapoured Zn film on the samples surface. The doping of Zn into InP was achieved by the method of Nd: YAG continuous laser inducing doping, and the PN junctions were obtained. The samples, which were irradiated, were studied with an Electrochemical C-V profiler and Scanning Electron Microscope (SEM). The relation of performance parameters of PN junctions such as the depth of the junctions, the distribution of the doping concentration and the irradiation time, the irradiation power are presented . The experimental results show that the acceptor concentration of uniform distribution, shallow junction (-1 μm), and heavy doping concentration is attained (-1019cm-3). The primary mechanism of Zn doping is assumed that alloy junctions came to being with the laser irradiating.

    Oct. 01, 2002
  • Vol. 19 Issue 5 467 (2002)
  • [in Chinese]

    The excitement of second electron in electron multiply process is a gain process actually, which obeys certain distribution rules. The gain is a randomized quantity. The characteristics of input-utput of electron multiply system can be described by a noise factor usually. Because the noise factor is connected with input signals, it can't be used to characterize the gain of multiplication. In this paper, one concept of gain variation factor is given to describe the gain characteristics. Based on the analysis to cascading system of electron multiplication, one more general hypothesis about multiplication process statistics is prompted, and the expressions of noise factor and gain variation factor in cascading multiplication system and their relationships are given.

    Oct. 01, 2002
  • Vol. 19 Issue 5 471 (2002)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The 3D Laser Doppler Velocimeter (LDV) system was used to study the fire whirlwind flow field induced. The fire whirlwind characteristics parameters, induding radial velocity, tangent velocity and axial velocity, were obtained from the observation and masurement of the fire whirlwind by the infrared thermography and the themocouple. This experiment deepened the understanding of the mechanics of fire whirlwind entrainment and laid a good foundation for experiment study of fire whirlwind entrainment in the next step.

    Oct. 01, 2002
  • Vol. 19 Issue 5 476 (2002)
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