Barium atom is one of candidates for optical atomic clock. Laser cooling and trapping the atom need sufficient spectroscopic information of relevant energy levels. The excited energy level 6s6p3P1 is very important in the experiment of laser cooling and trapping barium atoms. Hanle effect was examined both theoretically and experimentally for the 6s2 1S0 to 6s6p 3P1 transition at 791 nm. A theoretical model was developed to include the influence of linewidth and intensity of probe laser on the fluorescence of Hanle effect. By fitting the experimental measurement with the model, lifetime and transition probabilities of 6s6p 3P1 state to lower states were obtained and found to be in good agreement with other reports.

Aimed at the access of high resolution CCD compressed video in aerial photography and measurement, a quick access scheme based on document structure is put forward. The access system consists of basic and detail image information. The realization structure of the system is proposed in practical memory. On the one hand, image basic information includes frame number, thumbnail, encoding length and address. Through frame number, image basic information is acquired and quick view is implemented. Furthermore, detailed encoding information can be accessed through related image detailed information. On the other hand, thumbnail displaying method based on wavelet transform is designed. Through above access structure, the whole access design was realized. Through the whole access system of compressed high-resolution CCD data, quick view and access were implemented rapidly and efficiently.

Based on the Lamé equation and Lamé functions, the perturbation method and Jacobi elliptic function expansion method are applied to construct the multi-order exact solutions to the cubic nonlinear Schr?dinger equation. Some new multi-order envelope periodic solutions are found among the nonlinear evolution equations. These multi-order envelope periodic solutions correspond to different periodic solutions, which can degenerate into the different envelope solitary solutions. It is shown that some multi-order asymptotic periodic solutions to some nonlinear evolution equations in term of Jacobi elliptic functions and Lamé equation are explicitly obtained with the aid of symbolic computation.

A new algebra method for constructing exact solutions of nonlinear evolution equations is proposed based on the auxiliary equation. The method is simple and universal. It can give various types of exact solutions according to different parameters, which are helpful to seek more new exact solutions and explore properties of nonlinear evolution equations. Many kinds of explicit solutions including Jacobi and Weierstrass elliptic function solutions are obtained, some of which are new.

A series of explicit exact solutions with arbitrary functions for variable coefficients (2+1)-dimensional Burgers system are obtained for the first time by mapping method. Partial solitary wave structure of the variable coefficients (2+1)-dimensional Burgers system is analyzed by graphic analysis method, and a kind of special solitary wave structure namely kink solitary wave whose equilibrium position is varying with time is revealed.

Gain-switching and Q-switching are usual methods to obtain pulsed laser operation. For 1.3 μm wave band pulsed laser which is widely used in nonlinear optics, detection device used for optical communication second window and fiber sensor etc, gain-switching method is put forward to obtain the pulsed operation. Firstly, rate equation for the gain-switching is used to analyze the operation of laser. And the numerical simulation shows influence of the cavity length to pulse parameters. Secondly, the driver of LD is modulated to pump Nd:YVO4 laser working in the state of gain-switching. By decreasing the pulse width of the pumping current, the first pulse of relaxation is picked up. The 1.342 μm pulse with average power of 80 mW, pulse width of 200 ns, frequency of 200 kHz, peak power of 2 W and pulse energy of 0.4 μJ is obtained at last.

A miniaturized, widely tunable and fiber-type CW mid-infrared light source system based on DFG/QPM technique is successfully developed. In the system, the segmental tunable fundamental sources are adopted, and the specific tuning bands for the fundamental lights are realized by using electronically controlled optical switches. For pump lasers, three tunable ytterbium doped fiber lasers (YDFLs) whose total tuning bands ranging of 1050～1110 nm are adopted, and for the signal lasers, three erbium doped fiber lasers (EDFLs) with total tuning bands ranging of 1535～1600 nm are selected. A mid-IR DFG laser source module with the size of 440 mm×290 mm×500 mm was successfully developed. And the tuning range of the mid-IR module covers from 3054.5 nm to 4009.1 nm.

Transverse mode distribution and dopant profile are introduced in propagation-rate equations. An approximate numerical algorithm by multilayer method is presented to calculate the power of amplified signal and amplified spontaneous emission (ASE) in multimode fiber amplifiers. Numerical results of the propagation-rate equations before and after the improvement are compared. It shows that power filling factor is the key indication to describe the transverse mode competition behavior. Dopant profile makes great effect in mode selection and 60%～70% confinement of flat doping is more helpful in high-order mode suppression. ASE significantly drops and SNR increases when the ions are doped more concentrated in the fiber core.

The low and medium frequency intensity noise of the erbium doped fiber laser (EDFL) is suppressed by using optoelectronic feedback. The factors affecting the intensity noise of the EDFL are analyzed by the rate equations. The importance of the phase of feedback signal in noise suppression are discussed by simulating and optimizing the feedback circuits. The experiment results show that the peak relaxation oscillation (about 30 kHz) is reduced to about 35 dB, at the low frequency band (below 20 kHz) falls to about 10 dB averagely and the relaxation oscillation peak moving to the higher frequency is suppressed. The excellent noise property indicates that the laser source has important applications in optical sensors.

Considering dynamics of a pulse-driven finite-dimensional quantum system with near degenerate eigenstates, the multi-level system model includes one ground state and a number of excited states, in which the transitions exist between the ground state and any excited state. Population transfer induced by different kinds of pulses in this multi-level system were investigated. It is noted that in the case of both weak and strong fields, the quantum system can be reduced to a two-level system. Analytical relations between the original system and the reduced system are obtained for weak fields with multi frequencies and strong fields with one frequency. These results can be generalized to a multi-level system with several sets of near-degenerated eigenstates, and the conclusion can be utilized to identify the effective dimension of a quantum multi-level system controlled by laser.

A general expression of quantum discord for X structure density matrix was derived. The dissipative dynamics of non-coupled two qubits independently interacting with their reservoir was solved by the non-Markovian master equation in a single excitation state. Under the detuning spectral density, the quantum discord dynamics was discussed and compared in different coupling regime. The results showed that this expression was employed to any physical system having X structure density matrix, and the two variants of master equations were exploited in different coupled regimes in the description of quantum correlation dynamics. It is convenient to calculate the quantum discord for later study and provide certain reference about what kind of master equation used in different coupling areas.

A better scheme of probabilistic teleportation of a triplet W state is proposed, where the three three-qubit W states are taken as quantum channels. Compared with Yan’s scheme, instead of using Bell-state measurement, a new orthogonal basis measurement is proposed in the scheme. The receiver performs appropriate unitary transformation according to the sender’s measurements, the success of probabilistic teleportation can be improved to 20/27.

The dynamical characteristics of two linearly coupling solitons with a localized impurity in Bose-Einstein condensates are investigated by direct numerical simulations of the Gross-Pitaevskii equation with split-step Fourier method. It is found that the evolution of solitons depends on the impurity strength and linearly coupling parameters of the system, and there exist exchange, self-trapping and Josephson oscillator with the increasing of linearly coupling parameters. The effect of impurity strength of potential well on the evolution of solitons is little when some given values are taken.

The propagation properties of paraxial Hermite-elliptical Gaussian light beam in a strongly nonlocal nonlinear media are studied. As the characteristic width of response function is much bigger than the beam width, the nonlocal nonlinear Schr?dinger equation is simplified and the strongly nonlocal model with elliptic-symmetry medium response function is obtained. Using method of separation of variables, the analytic solution of Hermite-elliptical Gaussian spatial optical soliton and the conditions in which it forms are also derived. Further investigation shows that with increasing of rank of Hermite- elliptical Gaussian spatial optical soliton, the light beam width increases, the degree of non-locality of medium relatively weakens. To obtain high-rank elliptical Gaussian spatial optical soliton, the degree of non-locality of nonlocal medium must be raised. The lowest-rank Hermite-elliptical Gaussian spatial optical soliton is just elliptical Gaussian spatial optical soliton.

The cylindrical surfaces of potassium dihydrogen phosphate (KDP) single crystal grow very slow and the conical surfaces grow fast during the crystal growth under traditional method. A KDP single crystal with large cross section (8 mm×22 mm×45 mm) is gained at some constant temperature by vaporizing the solvent in the experiment. The experiment can be used for reference of KDP single crystal growth by pulling method. Compared with the traditional method, the growth rate along the cylindrical surface is improved effectively, especially the direction downward, which is on account of the dropping of liquid level and continued change of solute boundary layer. The experience in purifying and preheating the solution and choosing the initial temperature is accumulated. The experiment is also useful for future KDP crystal growth research.

A “sphere plus plate”-composed Au/Ag nanostructure arrays with strong surface-enhanced Raman scattering (SERS) activity are fabricated through the templated method, and the SERS spectrum of polychlorinated biphenyl-77(PCB-77) based on this nanostructure is investigated. The results indicate that the characteristic Raman-shift peaks of PCB-77 may be observed with the bare SERS substrate, but the signal-to-noise ratio of SERS spectrum is too low. By functionalization-modifying decanethiol (DT) on the surface of the bare SERS substrate with the help of the interaction between the -SH group of DT and novel metals, the SERS spectrum of PCB-77 is obviously improved. With the optimal functionalization-modified SERS substrate which is soaked in the DT solution for 36 h, the characteristic Raman-shift peaks’ intensity of the SERS spectrum of PCB-77 gets enhanced greatly.

The harmonic oscillator of three-component acceleration seismic geophone based on photoelastic effect is designed by the methods of inertia force perpendicular to the harmonic oscillator and differential detection technology. In terms of dual M-Z interferometer of three-component acceleration seismic geophone, equal division of optical power and single-mode transmission of light are the bases of correct acceleration detection. The structure of M-Z interferometer is introduced. The optical field transmission of dual M-Z interferometer in three-component acceleration seismic geophone is simulated by the waveguide optics simulation software OptiBPM v9.0, and the optical field transmission graph of dual M-Z interferometer is obtained. The simulation result shows that when the light emitted from the laser passes through the dual M-Z interferometer, the optical field peak values of 1/4 branch waveguides all achieve 0.52, and the splitting ratio is 1:1:1:1. The equal division of optical power is realized, and the harmonic oscillator designed meets the demand of proper acceleration detection of three-component acceleration seismic geophone.

The Hamiltonian of a quantum rod with an ellipsoidal boundary is given after a coordinate transformation, which changes the ellipsoidal boundary into a spherical one. The first excited state energy, excitation energy and the transition frequency between the first excited state and ground state of the weak-coupled impurity polaron in it were studied. The effects of the transverse and longitudinal effective confinement lengths, the Coulomb bound potential and the ellipsoid aspect ratio are taken into consideration by using linear combination operator and unitary transformation methods. It is found that these quantities are increasing functions of the Coulomb bound potential, whereas are decreasing functions of the aspect ratio and the effective confinement lengths. These can be attributed to the interesting quantum size confining effect.

It’s indicated that the result of Nash equilibrium of noncooperative power control game in multicell wireless data networks can’t be Pareto optimality. A new power control algorithm based on best equal SIR is presented for multicell wireless data networks. Numerical results suggest that this algorithm can improve capability of the system, make terminals enjoy higher utility and lower transmit power, and the use of wireless resources become more rational and impartial.

Using the transfer matrix method, the dispersion curve and reflection spectrum of the metal-cladded uniaxial crystal waveguide structure are obtained. The waveguide modes of metal-cladded anisotropic planar waveguide can be excited by free space light, and the optical axis orientation of the uniaxial crystal modulates waveguide modes of the structure, makes Ey, Ez coupled into a hybrid waveguide mode (HGM) in the waveguide layer. By adjusting the coupling metal film thickness, polarization of the reflected light from the waveguide can be manipulated to realize TE-polarized incident light converting into TM-polarized output light or linearly-polarized incident light into circularly-polarized output light.