The structure of hydrogen molecule is the simplest in the universe, while its neutral cluster is a research prototype of molecular cluster science. At present, the study on the structures and dynamics of hydrogen clusters is still one of keystones in the research of basic sciences. Meanwhile, emphases of experimental and theoretical studies of hydrogen clusters are focused on the following three aspects including formation conditions and size distribution, ionization energy or appearance energy, and computation of quantum chemistry. The present status on the experimental and theoretical studies of hydrogen clusters are introduced comprehensively. At the same time, the progress of the photoionization of hydrogen clusters accomplished in our group are also introduced. It’s expected that some information is provided for the basic and application research of hydrogen clusters in the future.

Convex aspheric surface testing is very difficult. In order to obtain better wavefront error, a method including back null compensation with auxiliary surface was proposed. This method, based on third-order aberration theory, the ability of auxiliary surface to compensate the normal aberration of convex asphere with eccentricity of －1/n2<e2<1/n2 was investigated. There are two functions of the auxiliary surface. One is to make the center of the asphere locate in the air. The second is using the combination of auxiliary surface and convex aspheric surface to compensate the normal aberration of convex asphere. When －0.5<e2<0.5, the value of RMS, which is calculated by theory and Zemax, is better than λ/30. Furthermore, the surface figure accuracy can be practically reach λ/100 by using above testing method. In conclusion, the back null compensation with auxiliary surface testing is able to achieve better wavefront error.

In order to improve the performance of image enhancement under different illumination conditions, an effective image enhancement method was proposed, which was based on the improved histogram equalization and Retinex algorithm. First, the low frequency components of the image were obtained using the ideal low-pass filter and its dynamic range was optimized by the improved histogram equalization. Second, the high frequency components of the image were estimated by the guided image filtering, which replaces the Gaussian filter in Retinex algorithm. Finally, the estimated results were amplified by the linear processing method. Experimental results show that the performance of the proposed method was better than the traditional Retinex algorithm and improved histogram equalization algorithm by the subjective and objective evaluation. Furthermore, the proposed method effectively improves the image’s visual effects and intelligibility with strong robustness.

Using the classical Lie group method, the symmetries and reductions of (2+1)-dimensional potential Boiti-Leon-Manna-Pempinelli (PBLMP) equation were obtained. At the same time, a great many of solutions were derived by solving the reduction equations, including the rational functions, hyperbolic functions, trigonometric functions solution and Jacobi elliptic function solution.

People are always interested in solving the problem of one-dimensional nonlinear Schr?dinger equation with the fifth power. However, only a limited number of new solutions consisting of the elliptic and hyperbolic functions were obtained. In order to obtain a new infinite sequence solutions of one-dimensional nonlinear Schr?dinger equation with fifth power, it makes a series of transformations on the equation, and using the related conclusions of B?cklund transform and nonlinear superposition formula of Riccati equation the new infinite sequence solutions of one-dimensional nonlinear Schr?dinger equation with the fifth power consisting of trigonometric function, hyperbolic function and rational function were constructed.

An improved design of Faraday optical isolator at 780 nm was developed. Numerical simulation was used to confirm the design. It has advantage of more uniform magnetic field, smaller size and better isolation. This design of magnet called style “π” divides a whole hollow cylinder into 3 parts including several fan-shaped magnets. It can increase the use ratio of the remanence of magnet. The design of one-stage isolator has a volume of 52 cm3 with a volume of magnet of 18 cm3, which is small. The optical clear aperture is 5 mm with a 34.6 dB isolation and 90.9% transmission rate. Style “II” may also be optional for having a smaller volume but less uniformed magnets. The isolator developed according to style “π” has better performance than common used optical isolators in terms of atomic, molecular and optics (AMO) physics at the special wavelength of 780 nm in order to meet the demands of the ultracold atom system.

In order to meet the need of laser frequency shift and precision sweep in cold atom interferometry experiments, a control system for acousto-optic modulator with digital interface was designed and implemented. The control system consists of three components, namely upper computer (PC), microcontroller (ARM) and radio-frequency generator (DDS). Among them, PC is used to collect control information. ARM chip controls the DDS chip according to control information, so that the DDS chip can generate a RF driving signal for acousto-optic modulator, and obtain the desired laser frequency for experiments. The control system can output RF signals with frequency of 0～150 MHz and phase noise as low as －116 dBc/Hz. Meanwhile, the amplitude, phase and frequency sweep rate and other parameters of the output signals can be controlled efficiently. Additionally it offers a variety of operating modes to meet different requirements in cold atom interferometry experiments.

2.7～3μm laser, which has the important value of medical and military applications, are obtained from the transition 4I11/2 →4I13/2 with rare earth Er3 + as the active ions and YSGG, GGG, GSGG, YAG, YLF as the matrix material. Under 790 nm pump, the Er:YSGG as laser material can produce 2.79 μm stimulated emission. By building the rate equation of Er:YSGG energy level transition, the system characteristics of rotating mirror Q-switched laser were analyzed and numerical simulations were carried out. Result of the numerical simulations comprehensively shows the influence of system variables on the performance of rotating mirror Q-switched laser. These conclusion will provide theoretical guidance for the laser design and improvement of similar experiment.

A laser diode (LD) driving system was presented, which mainly contains high-stable temperature control circuit, high-stable current control circuit and protection circuit. Concrete circuit was given. The laser can work stably by simultaneously control the current and temperature precisely. The protection circuit can provide sufficient protection to LD during its working. Without it, LD can be easily damaged by false operation or other reasons. Experimental results show that the output wavelength of the LD under constant temperature (room temperature) drifts no more than 0.6 pm. When the environmental temperature changes from 10°C to 50°C, the drift is no more than 16 pm, which, accordingly, can be applied to circumstances that request for high stability of LD.

Based on the Gross-Pitaevskii (G-P) energy functional, the Anderson localization of a weakly-interacting Bose-condensed gas in a controllable speckle potential was investigated by means of split-step Fourier spectral method. The conclusions are as following. 1) The Gaussian-like exponential ansatz achieves good results in variation analysis. 2) Under the condition that disorder strength η is 1, interaction between atoms κ is 0.1 and characteristic intensity of speckle potential Vs is greater than 0.6 times of chemical potential μ, Bose-condensed gas can maintain a stable localized state during evolution. 3) The larger interaction between atoms goes against the formation of a stable Anderson localization when κ is greater than 5. 4) Under the condition that Vs is 0.6 μ and κ is 0.1, Anderson localization of Bose-condensed gas is more notable as the disorder strength of speckle potential η increases.

The reversible comparator circuit was further optimized in order to improve the universality of reversible comparator. The logical relationship of inputs and outputs in comparator were analyzed. A one-bit reversible comparator (OBC) and a one-bit reversible complete comparator (OBCC) were presented and designed. The two devices can be cascaded and rapidly generated into a reversible circuit of universal reversible comparator. Compared with the related literatures, the cascaded method efficiently decreases the quantity of constant inputs and garbage outputs, meanwhile it has the lower quantum cost, which is prone to the comparison with two multi-bit numerical values in reversible circuit.

A novel quantum secret sharing (QSS) scheme with a trustful center was proposed, in which the qubit generating devices and the qubit measuring devices were only equipped at the center. The center can provide the users with quantum states and measure quantum states from the users. The users only perform unitary operations and exchange operations to transmit the secret keys and prevent eavesdropping. Simultaneously, the cooperative operations must be performed between Bob and Charlie to obtain the secret keys. The theoretical analysis shows that the scheme is immune to the conventional attacks in QSS, such as the intercept-and-resend attack, the entangle-and-measure attack and the correlation-elicitation attack, etc. As the numbers of qubit generating and measuring devices are reduced greatly, the scheme provides a practical way for QSS technique with less cost.

The entanglement properties of photon and atom within semiconductor resonance cavity were chosen as qubits, atom state was transformed to photon state through electrodynamics system of semiconductor resonance cavity. According to the operation characteristics of semiconductor resonance cavity, judgment conditions of weak and strong coupling of atom and photon in semiconductor resonance were proposed, also the quantum state of atom was manipulated by utilizing external electromagnetic field, the operation of quantum logical gate was thereby completed, then the qubits were expanded though the entanglement among each cavity quantum electrodynamics (CQED) system, realizing the quantum computing and networking. Various models were introduced such as micro disc resonance cavity, single quantum dot, and so forth, which would benefit turning the conception of quantum computing and communicating into the development and manufacturing of semiconductor quantum devices.

Based on the non-locality entanglement correlation of W state, a quantum secret sharing protocol was proposed by utilizing quantum teleportation. In the proposed protocol, Alice prepares a three-particle W state, and sends any two-particle of the W state to Bob1 and Bob2, respectively, then performs Bell bases joint measurement on her own particles. According to Alice’s measurement result, Bob1 and Bob2 can jointly obtain the secret information by performing corresponding local operations. The security of the proposed protocol was analyzed in detail. It is shown that the proposed protocol can resist several attacks, such as intercept-resend attack, entanglement-and-measure attack, and etc.

Using the numerical method, the information entropy and evolution of entanglement of atom and a single mode light field of Jaynes-Cumming (J-C) model in the Kerr effect medium cavity were studied. The influence of Kerr effect on the properties of entangled states was obtained. The results show that Kerr medium has a strong influence on entanglement property of coupled system. With the appropriate Kerr effect, the maximally entangled quantum state will remain long.

Based on the waveguide-two-cavities-quantum-dot system’s Hamiltonian and Heisenberg equation of motion for system operators, the input-output relations of the optical modes were derived. Moreover, using the Green function theory, the coupling rate between the cavity and waveguide was analytically defined. Based on the above, the analytic solution of the transmission spectra was derived. By numerical calculation, the transmission spectra of the whole system were investigated with varying optical length (which induces the phase separation between the two cavities) and detuning factor between the two cavities. The results reveal that the transmission spectra are closely dependent on the distance and detuning of the two cavities. This structure has potential applications in quantum information, quantum computation and optical switch.

Transmission line and equipment corona of transformer station can be used to locate defect and analyze real situation of insulation. A UV imager based on solar blind filter and MCP detector was described. This instrument worked with visible light video camera in the same visual field and high sensitivity detection and location for corona were realized. In order to test the performance of UV imaging detection, high voltage point discharge equipment was used in experiments of different discharge intensities and on-site corona discharge detection. Results showed that the developed UV corona imager could be applied in detecting high voltage corona and locating fault.

A general method to calculate various transmission coefficients for two-terminal systems based on tight-binding models with fluctuating on-site energies in the scattering region was presented, then, a two-dimension H-shaped quantum dot array of four-terminal system based on real-space lattice models was presented. Problem of the quantum transport in a four-terminal system can be reformulated into a problem of the quantum transport in an effective two-terminal system and then be treated using a standard two-terminal method. By exploiting real-space Green’s functions, the transmission coefficients of four-terminal quantum dot array were calculated, and the problem of quantum transport was treated.

The influences of electric field and temperature on properties of strong-coupling bound megnetpolaron in parabolic quantum wires were studied by using the linear combination operator and the unitary transformation methods. The relations of the ground state energy, mean number of megnetphonon and vibrational frequency in parabolic quantum wires with the confinement strength, cyclotron resonance frequency and electric field were calculated. The numerical results show that the ground state energy increases with the confinement strength, cyclotron resonance frequency and electric field, however, it decreases with increasing of temperature and the coupling strength. The mean number of phonon is an increasing function of the temperature and confinement strength and cyclotron resonance frequency. The variation frequency increases with increasing of the cyclotron resonance frequency and confinement strength.