Chinese Journal of Quantum Electronics
Co-Editors-in-Chief
Zhiben Gong
2014
Volume: 31 Issue 1
18 Article(s)

Feb. 26, 2014
  • Vol. 31 Issue 1 1 (2014)
  • Juan-juan QIN, Wei-wei DONG, Shu ZHOU, Li-bing YOU, and Xiao-dong FANG

    Extreme ultraviolet lithography (EUVL) has become the key candidate of lithography tools to manufacture devices at the 22 nm node and beyond of semiconductor integrated circuit, which makes use of the extreme ultraviolet rays with 13.5 nm wavelength as the light source. It is one of approaches to construct a normal incidence optical system by using the excellent performance multilayer coatings. A review was given of the specification of the coatings for EUVL and the recent progress in multilayered systems. The key deposition methods and equipments that produce such coatings were discussed. Furthermore, in terms of high reflectance, wavelength matching, profile matching, life and stability, it also concludes the problems existed in the preparation technologies of the multilayered systems and the future development direction.

    Feb. 26, 2014
  • Vol. 31 Issue 1 1 (2014)
  • Mei-hong LU, Hai-ying LEI, Zhi-jun WANG, and Qiao-feng WU

    Fluorescence spectrometer and confocalmicro-Raman spectrometer were used to study the fluorescence spectroscopy and Raman spectroscopy of several synthetic food colors. On one hand, the fluorescence spectra of different concentrations were first measured and the spectral characteristics were discussed. On the other hand, the Raman spectroscopy of carcinogenic organic amaranth sample was studied as an example. In order to improve the detection sensitivity, 55 nm gold nanparticles collosol as substrate and 785 nm excitation light were used to study the surface enhanced Raman scattering spectrum of amaranth with different concentrations, and the detected minimum concentration was 10-17 mol/L. The results provide spectrum experiment basis for reasonable utilization of the artificial color and the safe and rapid detection, also provides a new method for safety testing of other artificial color.

    Feb. 26, 2014
  • Vol. 31 Issue 1 12 (2014)
  • Si-yang CHENG, Min-guang GAO, Liang XU, Ling JIN, Sheng LI, Jing-jing Tong, Jian-guo LIU, and Wen-qing LIU

    A remote sensing system was developed based on direct-sun infrared absorption spectroscopy, which was running continuously in Hefei, Anhui. The total atmospheric transmittance was measured from the solar absorption spectrum and modeled by line-by-line calculation. The column concentrations of methane and oxygen were inversed from measured total atmospheric transmittance by nonlinear least squares spectral inversion algorithm. The column concentration of oxygen was used as internal standard function to obtain column-average dry-air mole fractions of methane and the precision was better than 2%. The column-average dry-air mole fractions of methane, from 12:00 to 15:00 on September 25, 2012, were compared with methane results observed by Japanese greenhouse-gases satellite over this site during the same period, showing that the relative deviation was less than 1%. Obviously, this system and algorithm are an effective way to detect methane column concentration with higher precision.

    Feb. 26, 2014
  • Vol. 31 Issue 1 18 (2014)
  • Li DING, Kun HUANG, Xue-liang KANG, and Yong-ping LI

    Diffractive optical element (DOE) has unique dispersion characteristics and flexible design freedom. The cascaded DOE was applied in the concentrator system of solar cell to achieve focusing, shaping and spectrum separation function and the design methods and algorithms were presented. Seven regular shaped and completely separated spots were observed on the target surface when simulating with the mixed seven-wavelength light. It is proved that the cascaded DOE structure can effectively enhance the efficiency of solar energy utilization.

    Feb. 26, 2014
  • Vol. 31 Issue 1 25 (2014)
  • Xiu-fang TIAN, and Cong-feng WU

    In the particle acceleration by stimulated emission of radiation (PASER), the energy stored in an active medium transfers directly to the electron beam passing through in discrete amounts by emitting a photon when the bounded electron returns from upper to lower energy state. The wake-field generated by a bunch of electrons traversing in an active medium was discussed. The calculations of the development of amplitude for gas mixture active medium about CO2 and ArF were taken respectively. The results show that the gradient can reach around 1 GeV/m,which is about two orders of magnitude larger than that in normal acceleration structure (such as disk-loaded waveguide acceleration structure) in present. In addition, the electron energy gain occurring as a train of electron micro-bunches traversing in gas mixture was analyzed by a two-dimension model. The train of micro-bunches can obviously gain energy from the active medium and energy exchange is linearly proportional to the interaction length d. The influence of the bunch figure and other quantities on the energy exchange occurring as a train of electron micro-bunches traversing CO2 gas mixture was investigated when the interaction length is 0.5 m. The results illustrate that maximum electron energy gain can be obtained by the train of micro-bunches with optimized parameters.

    Feb. 26, 2014
  • Vol. 31 Issue 1 33 (2014)
  • Ying-hua JI, Jian-hua HUANG, and Yong-mei LIU

    In quantum information transfer process, the role of environment leads decoherence and disentanglement. Using the advantages of different types of qubits to constitute a hybrid qubits system is a useful way for overcoming decoherence effects and achieving quantum information transfer. It’s found that through combining the energy loss in the process of information exchange of qubits (exchanging decay between the qubits) and the decoherence effects of the external environment, people can achieve quantum information transfer with no decoherence effects. And the constraint relations matching exchange decay rate and decoherence time in no decoherence effects quantum information transfer were obtained.

    Feb. 26, 2014
  • Vol. 31 Issue 1 40 (2014)
  • Bing XU, and Fang-sen XIE

    The Pancharatnam phase properties of two coupling-atoms and a single-mode squeezed state light field in nonlinear Kerr medium were studied. Selecting proper initial conditions to solve the Schrdinger equation by the rotating wave approximation, and the Pancharatnam phase specific form was obtained. The results show that the two coupling-atoms’ initial states are in any form, the Pancharatnam phase frequency increases when the interaction strength between atoms and light field, and the dipole-dipole coupling strength between two atoms or the Kerr medium’s nonlinearity increases. The Pancharatnam phase evolution shows obvious trend of oscillating and rising(or fall) when the initial state is that two atoms are both in the excited states. As the growth of the Kerr medium’nonlinearity, the Pancharatnam phase evolution becomes disordered when the initial state is that just one atom is in excited state.

    Feb. 26, 2014
  • Vol. 31 Issue 1 47 (2014)
  • Hai-long ZHOU, Qiang ZHU, Bing WANG, and De-zhi XIONG

    For Bose-Einstein condensates in one dimensional optical lattice, the phase fluctuation is a significant quantity in the investigation of quantum phase transition. A method to measure the phase fluctuation was investigated by comparing the contrast of interference peaks obtained from experimental absorption images and simulated data sets. Phase variances of condensates in optical lattices with different depth were measured by this method. The phase fluctuations increase from 0.29π to 0.69π when the depth of optical lattice varies from 5.6ER to 30.7ER.

    Feb. 26, 2014
  • Vol. 31 Issue 1 56 (2014)
  • Hong-xing LI, Sachuerfu , Chuan FENG, and Dong-xia ZHANG

    Using negative entropy method, the quantum entanglement characteristics of the system of binomial optical field interacting with moving atom were studied. The influences of the atomic initial state, field-mode structure parameter, maximum photon number of binomial field, coefficient of binomial field, transition photon number and detuning were discussed. The results show that the value of entanglement degree of the system appears regular evolution and entanglement sudden death (ESD) phenomenon when atomic motion was considered. The increasing of the field-mode structure parameter shortens the period of the entanglement and results in a slight decreasing of amplitude. The atomic initial state affects the entanglement degree of the system. When the atomic initial state tends to pure state, the entanglement degree of the system is larger relatively. With increase of the maximum photon number of binomial field, the value of the entanglement degree of system becomes small, but the period for regular evolution is almost unchanged. When the field is in the middle states, the entanglement degree is smaller relatively. With the increase of the transition photon number, the value of the entanglement degree of the system becomes larger, the period of the oscillation becomes shorter, meanwhile the oscillation of the system becomes faster and faster. With the detuning increasing, the entanglement becomes small.

    Feb. 26, 2014
  • Vol. 31 Issue 1 61 (2014)
  • Ai-li LI, Ya-fei YU, and Zhi-ming ZHANG

    Non-destructive identification of entanglement is very important in quantum information processing. A scheme is proposed which constructs a controlled phase shifter (CPS) gate via the cavity input-output process. The CPS gate can be used to construct a parity analyzer (PA) with homodyne detection technology. Moreover, it uses the PAs, combined with some other operations, to construct the non-destructive atomic Bell state and GHZ state analyzers. The scheme has two advantages. It uses the coherent light and homodyne detection, which are much easier to be implemented than single photon source and single photon detection. The atomic Bell state and GHZ state analyzers constructed are non-destructive. All the methods and techniques used in this scheme are achievable in the present experiment.

    Feb. 26, 2014
  • Vol. 31 Issue 1 69 (2014)
  • Xue-min ZHANG, Meng QIN, Bi-li WANG, and Cui-cui LIU

    The effects of different spin-orbit interaction on entanglement of a two-qutrit Heisenberg XX system with inhomogeneous magnetic fields were investigated by means of negativity. It is found that with increasing of the Dzialoshinskii-Moriya (DM) interaction, entanglement increases at high temperature, while it fluctuates at low temperature. In general case, the entanglement of x component Dzialoshinskii-Moriya (DM) interaction is higher than that of z component and it is on the contrary under certain conditions. So, entanglement can be controlled by varying the directions of DM interaction. Also quantum logic gate can be realized by using the symmetry and transition of entanglement.

    Feb. 26, 2014
  • Vol. 31 Issue 1 75 (2014)
  • Min HUANG, Wen-juan HAN, and Hai LIU

    The shortest time of the minimum eigenvalue of [N,k] of Heisenberg model (N is the total number of sites of Heisenberg chain , k is the number of electrons at site spin up) were obtained using parallel algorithm (Z equisection method, Z is from 1 to a, a is the number of the eigenvalue of [N,k]) in Fortran program. The energy matrix of [N,k] was produced by permutation group. The eigenvalues were obtained by diagonalling the energy matrix. The shortest (or longest) time of the minimum eigenvalue of [N,k] was obtained from the data group being made up of the eigenvalues using Z equisection method. The results show that the time is the shortest and same when Z is 1 or the number of the eigenvalue of [N,k]. When N(k) are same, k(N) increases and Z is same, the time acquisiting the minimum eigenvalue of [N,k] increases.

    Feb. 26, 2014
  • Vol. 31 Issue 1 80 (2014)
  • Guo-wei WANG, Qing-hua CHENG, and Da-hai XU

    By virtue of the Liouville equation and Novikov theorem, the approximate Fokker-Planck equation was derived, and the analytic expression of the stationary probability distribution (SPD) was obtained in an asymmetric bistable system driven by cross-correlated multiplicative white noise and additive white noise with periodic signal. Based on the computed results, effects of the following parameters, including intensity of noises and their correlation, the amplitude and frequency of the periodic signal, and the asymmetric parameter of system on the SPD were investigated. Numerical results show that: 1) The intensity of noises and their correlation, amplitude of periodic signal, and asymmetric parameter of the system can induce the SPD transition from bimodal to unimodal in structure, i.e., a non-equilibrium phase transition is generated. 2) There is no non-equilibrium phase transition as frequency of the periodic signal varies. 3) The structure of the SPD exhibits a symmetrical structure at x=0 in the case of r=0, while the symmetry of SPD at x=0 is destroyed if the asymmetric parameter of the system r≠0.

    Feb. 26, 2014
  • Vol. 31 Issue 1 86 (2014)
  • Jian GAO, Xiao-dong FANG, Xu LIANG, Yue MA, and Ben-ke WU

    Transmission characteristics of liquid-core optical fiber used for 308 nm excimer laser instrument in vitiligo treatment were studied. The optical transmission under different laser power output and operation time of three different fibers were tested and compared. These fibers included UV extended liquid-core optical fiber, silica bundled fiber and ordinary liquid-core optical fiber. The transmissivity of UV extended liquid-core optical fiber was as high as 70%. The intensity distribution and beam homogenization via optical fiber were measured and analyzed. The beam homogenization via UV extended liquid-core optical fiber was less than ±4.5%. The results showed that transmission system based on liquid-core optical fiber for 308 nm UV laser has better transmissivity, homogenization and stability.

    Feb. 26, 2014
  • Vol. 31 Issue 1 94 (2014)
  • Zhen-hua HU, Qiao ZHANG, Lei DING, Ying-ping WANG, Hai-yang ZHENG, and Li FANG

    In order to study the heavy metal elements in liquid by double pulse laser induced breakdown spectroscopy, double pulsed laser induced breakdown spectroscopy (DP-LIBS) was used, the LIBS characteristics of Cu elements in a vertical flow of aqueous solution of CuSO4 were measured and analyzed. Two Q-switched Nd:YAG lasers operating at 532 nm was utilized to generate plasma on a flowing liquid surface, and plasma signal by detecting the CCD grating spectrometer. The gate delay, the delay time between two lasers of DP-LIBS were investigated experimentally. The results show that the intensity and SNR of Cu emission lines excited by double pulse is about 2 and 3.3 times than the intensity of line emission excited by the single pulse separately. When the delay time between two lasers at 2~3μs, emission line intensity reached maximum enhancement. The detection limit of metal ion in water solution under the optimized operation conditions was found to be 9.87 mg/L for Cu, which is about 6 times than single pulse. The results provide a basis for rapid detection heavy metals in water solution using DP-LIBS technique.

    Feb. 26, 2014
  • Vol. 31 Issue 1 99 (2014)
  • Da-qing ZHANG, Guo-bin LI, and Chang-shui CHEN

    Band gap of the Inx Ga1-x N was changed by doping with different concentrations of In content for changing the quantum well barrier height. The relationship between the type of barrier height and the power spectral density, internal quantum efficiency, light emitting power and recombination rate of the InGaN/GaN quantum well light-emitting diode was researched. The analysis results showed as follows: 1) In content of the light-emitting diode and optical properties is not a linear relationship. 2) When the current density is low, the smaller the In content, the greater the peak of the spectral density and power of the light emitting. 3) However, when the current density is larger, the greater the In content, the greater the peak of the spectral density and power of the light emitting. 4) The blue-shift associates with the size of the current density, when current density is large, blue-shift is big, the smaller the contrary. Therefore, the content of In should be selected according to the type of current density so as to improve the luminous efficiency.

    Feb. 26, 2014
  • Vol. 31 Issue 1 107 (2014)
  • [in Chinese]

    Feb. 26, 2014
  • Vol. 31 Issue 1 116 (2014)
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