Laser-induced plasma spectroscopy of metal materials including copper, magnalium and steel was investigated. The effects of delay time and ambient atmospheres on the emission characteristics of laser-induced plasma spectroscopy were studied. Experimental results show that proper delay time and ambient atmospheres of argon can notably enhance signal-to-noise ratio of spectra, thus the accuracy of elemental content analysis was improved.

An analytical expression for the on-axis spectrum of spherically aberrated polychromatic partially coherent light diffracted at an aperture was derived based on the propagation law of the cross-spectral density function. Spatially fully coherent result was obtained as a special case. The influence of spherical aberration on the behaviors of spectral switches was stressed. It was shown that spherical aberration may induce differences of spectral shift and changes of the critical position.

Ion mobility spectrometry (IMS) is difficult to identify some organic compounds with closed reduced mobility values, such as the isomeric compounds of xylene. A tandem analytical technique, UV photoionization ion mobility spectrometry (UV-IMS) coupled with a packed column gas chromatography (GC), GC-UV-IMS, was developed for the efficient separation and detection of aromatics compounds. The gas chromatograms and ion mobility spectra were measured at different column temperatures and the flows of nitrogen carrier gas in order to obtain optimized experimental parameters. The gaseous mixture of benzene, toluene, o-xylene, m-xylene and p-xylene was detected with a homemade GC-UV-IMS apparatus. The results show that three isomeric compounds o-xylene, m-xylene and p-xylene can not be distinguished when only using the UV photoionization IMS. However, two dimensional gas chromatogram-ion mobility spectrum can greatly enhance resolution of these organic compounds on the basis of their retention time and drift time. This demonstrates that the established GC-UV-IMS has a good ability to discriminate and detect trace volatile organic compounds.

The experiment of optical-microwave double-resonance in trapped mercury is the basis for the research of mercury ion microwave frequency standard. The second-order Zeeman effect is one of the important factor affecting frequency stability and the magnetic field effect. The Zeeman spectrum of ground state of trapped 199Hg+ ion was measured by the method of optical-microwave double-resonance. The clock transition frequency and linewidth of the clock transition line were obtained by scanning the microwave frequency in a narrow region. The magnetic field in trapping area was shielded by the materials of permalloy. The linewidth of the clock transition line is decreased to about 1.5 Hz. Comparing the clock transition frequency without magnetic shielding, the clock transition frequency of magnetic shielding decreases 13.5 Hz. According to the second-order Zeeman effect, it’s calculated that the magnetic field of trapped region is about 0.1 Guass.

Laser imaging tracking system is a potential way of tracking dark target in distance especially in space, but target image under the illumination of laser is modulated by the laser speckle and it will affect the identification and orient precision of target. Analysis of the statistical characteristics of laser imaging is given, a combined numerical filter depressing the image noise that utilize gray level linear transformation, median filtering and Lee filtering acting on the original image in turn is provided. The results indicate that the noise coefficient is reduced from 0.67 to 0.22, and edge-preserving degree is up to 0.96, respectively, and it makes a necessary basis for the following image processing.

The multiple solitary wave solutions of a variable coefficient forced Burgers equation were obtained by using homogeneous balance method. The graphic analysis method is used to analyze the interactions among the special kink solitary waves. Some new phenomena were observed, such as merger and split due to the interactions among kink solitary waves which are arisen under the forced effects in the inhomogeneous media. The results show that the merged (or split) special kink solitary waves can continue to oscillate and propagate, or neither oscillate nor propagate, or oscillate in the original position but not propagate.

A novel controllable cold neutral atom guiding scheme based on parallel current-carrying wires and bias magnetic field is proposed. Magnetic field distribution in cross-section at different transverse bias field Bbx is calculated. The centre of magnetic traps is discussed. Single-channel and double-channel magnetic guiding can be realized. Based on this scheme, an atom beam splitter, which has adjustable splitting ratio, is designed by adding a longitudinal magnetic bias field Bby. The transverse distribution of magnetic trap is calculated, and the magnetic contour plane of the splitter is shown. By using the classical Monte-Carlo method, the splitting process is simulated, and this scheme is validated by the simulation results. Splitting ratio between left and right guide changes from 0.9/0.1 to 0.1/0.9 when longitudinal magnetic bias field Bby changes from -0.005 G to 0.005 G.

To construct a tight frame for a given vector, joint quantum measurement of teleportation was investigated, and a construction method of tight frame was proposed. The generalized construction method of tight frame is based on joint quantum measurement. Firstly, arrange the given vector into a coefficient matrix, then obtain its left unitary, right unitary and singular value matrix by singular value decomposition. Secondly, find a base including a column whose coefficient matrix is just the non-zero part of the singular value matrix. At the end, arrage the rest colomns of the base into non-zero part of the singular value matrix, then get the rest tight frame columns by singular value reconstruction.

Using the two times quantum teleportation, a quantum identification scheme of cross-center based on four-qubit cluster state is proposed, and the identification for user in distributed network is realized. In this scheme, the identification system consists of main server and client server, and the communication between main server and client server is performed using the four-qubit cluster state as quantum channel. All the operations of any user are processed at client server and there is no direct communication between user and main server. All authentications are processed by servers based on the principles of quantum mechanics, and its security is guaranteed by quantum mechanism. Finally, the security of the quamtum identification scheme is analysed.

The evolution of entangled decoherence of coupling superconducting qubits in non-Markovian environment is investigated in detail using concurrence function. The results show that, for coupling superconducting qubit under different entangled initial states, because of the role of memory feedback due to environmental effect, the entanglement of coupling superconducting qubits under a thermal bath always tends to zero monotonically. Further results also showed that, the sudden death of entanglement will soon occur in non-Markovian process, stronger the dissipation, faster the death of entanglement. But in Markovian process, it tends to death of entanglement slowly.

The atomic entanglement dynamics is studied in the double Jaynes-Cummings model composed of two coupled cavities. Effect of the cavity-cavity coupling constant A and the atomic initial states on entanglement sudden death (ESD) and entanglement sudden birth (ESB) is analysed. By studying the atomic concurrence, it was shown that when the atomic initial states are the first kind Bell-like states, ESD and ESB doesn’t appear, coupling of the cavities can increase the atomic entanglement and entanglement occurs even the initial states are disentangled. When the atomic initial states are the second kind Bell-like states, the time intervals between the ESD and ESB, and whether the ESD occurs or not are controlled by the coupling constant A. The atomic entanglement can’t be produced by the coupling between the cavities when the atomic initial states are disentangled and in the second kind Bell-like states.

The wavelength and angle dependent optical transmission of two-dimensional photonic crystal slab are calculated using rigorous coupled wave analysis (RCWA) method. The relationship between guided resonance of spectrum and the band structure of two-dimensional photonic crystal slab is investigated. Based on InP material photonic crystal slab, angle resolved and wavelength resolved optical switches are designed utilizing the characterization of low transmission and high quality factor of guided resonance. These switches operate at the wavelength of 1550 nm. It shows that the quality factor of guided resonance mode in the transmission spectrum can reach 105, and achieve an on-off contrast of nearly 100% with the nonlinear refractive index change of 10-4. As the signal light and pump light couple with the guided resonance modes of photonic crystal slab respectively, the field intensity of pump light is enhanced, and the pump energy is reduced to only 184 fJ. To our knowledge, this is the lowest energy needed for optical switcher.

In order to discuss the soliton transmission characteristics in dispersion management system, the following cases that the averaged dispersion of dispersion map is negative (anomalous) and positive (normal) are simulated respectively. The result shows that as depth of dispersion map changes stronger, pulses’ peak power and fluctuation of pulses’ amplitude become greater, and bright soliton can transmit stably in the averaged dispersion of positive, but transmission quality is poor, transmission distance is limited.

Turbulence intensity profile can be obtained by turbulence intensity profile lidar system through measuring a set of atmospheric coherence length. However, direct inversion from measured atmospheric coherence length data can result in a high noise gain. A new approach, which combines slope and Richardson method, was developed and its numerical simulation were performed. By recovering two representative Hufnagel-Valley(H-V) C2n profiles, the average relative errors between initial profile and recovery profile are 7.8% and 10.6%, respectively. Numerical results demonstrate that this method has a good precision.

The feasibility of real-time monitoring in laser induced interstitial thermotherapy (LITT) of biological tissues using near infrared spectrum technique is explored and validated. In vitro liver and rats with subcutantaneous implanted tumor models were chosen as experiment objects. Changes of absorption coefficient (μa) of tissue are real-time measured by near infrared spectrum system in laser induced interstitial thermotherapy. The result indicates that μa has some variations during LITT. The change law of μa invitro livers experiments is significant. It slowly goes up under low power, and rises greatly based on high power when biological tissues reach certain temperature(around 50°C). The change laws of μa during tumor experiments is different according to characteristics of tumor tissue which can be used for future clinical treatment. Experimental results show that μa has valuable reference as a real-time monitoring factor in LITT of entity organizations, but it also needs further study as evaluating factor of the tumor treatment appraisal.

Based on the framework of effective-mass approximation and variational approach, the influence of built-in electric field and impurity on the binding energy of a cylindrical wurtzite GaN/Alx Ga1-x N quantum dot(QD) with two electrons is discussed. The numerical results show that while the charge of impurity is negative, the impurity state is instable. When there is a donor impurity with positive charge e in the center of QD, the binding energy of impurity to electron firstly increases slowly, reaches a maximum value, then decreases with increasing the height and radius of QD. With increasing Al content, the binding energy increases monotonically. The binding energy of impurity to electron firstly increases, and then decreases with moving the impurity position from the bottom of QD to the top, there is a maximum. In comparison with the single-electron impurity states, the influence of the built-in electric field on the binding energy of two-electron quantum dot system is more obvious. While the QD height L6 nm, the binding energy of two-electron quantum dot system with impurity is smaller than that of the single-electron impurity states.

Effects of speed of polaron on properties of a strong-coupling magneopolaron in a quantum dot are studied by using improved linear combination operator and the unitary transformation methods. Relations of the vibrational frequency, ground state energy, effective mass and interaction energy of a strong-coupling magnetopolaron considering the influence of Rashba effect, which is brought by the spin-orbit interation, are derived in the quantum dots with speed of polaron. Numerical calculations for RbCl crystal are performed and the results show that the vibration frequency, ground state energy and effective mass of the strong-coupling magnetopolaron in a quantum dot increase with increasing of speed of poloran, and interaction energy of magnetopolaron decreases.

On the condition of electron-LO phonon strong coupling in a parabolic quantum dot, the eigenenergies and eigenfuctions of the ground state and first excited state using variational method of Pekar type were obtained. The system in quantum dot may be employed as a two-level quantum system qubit. The relations on the electron-LO phonon strong coupling, the confinement length with the electron probability density were investigated. The results indicate that the electron probability density increases with increasing the electron-LO phonon strong coupling and decreasing the confinement length. The results are meaningful for preparing a qubit.

Differential phase-shift keying (DPSK) format gained more attention for long-haul optical fiber communication systems, due to its advantages of improvement in receiver sensitivity, high spectral efficiency and robustness to nonlinear effects. Phase noise and nonlinear phase noise are the main factors impacting the performance of DPSK system. Phase noise is monitored and reduced by four-wave mixing (FWM) in a fiber experimentally. The results show that the products of FWM can monitor the value of phase noise, DPSK signals performance can be improved by a amplitude limiter in a fiber based on saturation FWM through reducing nonlinear phase noise. This result is very important for high-speed all optical communication.

In order to study the amplification and propagation characteristics of optical pulse in ytterbium-doped fiber amplifier, the propagation equation of optical pulse in distributed fiber amplifier is established. Using split-step Fourier transform method, the propagation state of optical pulse is simulated, and influence of frequency detuning on characteristics of optical pulse is discussed especially. The results show that optical pulse is amplified and broadened simultaneously in ytterbium-doped fiber amplifier, so it has a deformed profile and a broadening power spectrum. For the case of frequency detuning, the amplification of optical pulse has declined and symmetry of the pulse dispears. If the center frequency of optical pulse deviates from the gain peak frequency in different directions, the deformation law of pulse is different. Therefore, the influence of dispersion and nonlinear effect of fiber amplifier and frequency detuning on the propagation characteristics of optical pulse should be considered in the design of amplification system.