By using the Richards-Wolf vector diffraction theory, the focusing properties of Bessel-Gaussian radially polarized laser beams modulated with a diffractive optical element (DOE) in a 4pi focusing system were investigated which consists of two same high numerical aperture lens. Due to the adjacent ring interference of DOE, the intensity distribution near the focus is different from the intensity distribution without DOE modulation. The results simulated by Matlab show that the multifocal spherical spots can be obtained when Bessel-Gaussian radially polarized beam passes through this optical system. The number of spherical spots is associated with the number of belts of DOE and relative size of adjacent ring. The spherical focal spots can move along the optical axis if the relative phase of left and right of the incident beam is changed. The results show important applications in optical microscopy, optical data storage, and particle manipulations.

By applying the generalized algebraic method, the generalized (3+1)-dimensional Kadomtsov-Petviashivilli equation was studied. Some new explicit solutions of the generalized (3+1)-dimensional Kadomtsov-Petviashivilli (KP) equations were obtained, which included Jacobi elliptic function solutions, hyperbolic function solutions, trigonometric function solutions, and so on.

The wave soliton ansatz was performed for both the generalized fifth-order KdV and BBM equations. The soliton solutions for both the generalized fifth-order KdV and BBM equations were given. For the soliton solutions, to guarantee the existence of the above soliton solutions, the conditions of existence of soliton solutions were presented.

The high order harmonic generations (HHG) of three-dimensional hydrogen atom which exposed to the combination of two laser pulses were studied. When the combined field has a proper frequency ratio of 3:5, and the relative intensity of the additional laser field reaches a specific value (0.35), the single short pulse can be obtained directly. A new method to obtain the single short pulse is proposed, the main points of the method are the following. Frequency ratio of the two lasers should be adjacent odd, and the relative intensity of the additional laser to basic laser should fall on a particular value. In future research, the atoms with a higher binding energy can be chosen, and the width of HHG’s plateau will be enlarged, so the width of pulse will be reduced.

Pumping heavy water gas (D2 O) molecules using continuous operation carbon dioxide laser 9R(22) output line, continuous terahertz laser radiation output with 385 μm wavelength and 0.78 THz frequency can be produced. The laser process can be effectively analyzed with the semi-classical theory analysis method combining three level system model, and the solving process was simplified through reasonable approximation. The analytical expressions of terahertz laser signal gain coefficient Gs and pump light signal absorption coefficient Gp were obtained, and the pump threshold for producing terahertz laser oscillation was calculated to be 6.24×10－3 W/mm2. Normally, when the pump laser output spot area is 0.25 mm2, the output power of its 9R(22) spectral line needs to be above 1.6 mW for stimulating terahertz laser radiation.

By analyzing the heat generation in the quantum wells and heat transportation among wells of the quantum cascade laser (QCL), the heat transport equation was acquired. After that, comparing it to circuit theory, the equivalent circuit model can be established. Then, using some relevant program, the theoretical and circuit simulation were carried out, and its characteristics of generating heat can be obtained. Meanwhile, some factors were anlyzed which can affect its heat generating characteristics.

In view of the stability problem that the optical fiber Mach-Zehnder interferometer (MZI) is easily impacted by the environment, an MZI experimental system was designed. The output intensity of the optical fiber MZI was analyzed theoretically and validated by experiment. The relationship between the stability of MZI and environment and the impact of phase modulation on the interference were also revealed intuitively by oscilloscope. A new phase compensation scheme was designed to overcome the instability which results from vibration noise, temperature variation and so forth. The scheme can realize phase difference detection and feedback control.

The joint detection probability of orbital angular momentum entangled photons of spontaneous parametric down conversion process was studied. In the case of ignoring the polarization of photon with a thin crystal, expression of the joint detection probability of orbital angular momentum entangled photons was derived. It’s shown that in the spontaneous parametric down conversion process, choice of pump photon, signal photon and idler photon, size of their parameters (waist, orbital angular momentum and radial index) affect the joint detection probability of entangled photons.

In order to improve the security and efficiency of quantum key distribution protocol, a protocol was proposed based on entanglement swapping. The two parties of communication establish the key by performing the Bell state measurement. No other people can get the key without being found. Different from the proposed protocol, the Bell measurement of any two Bell states can be realized to achieve the purpose of quantum key distribution. It does not need multi-particle entangled state but only EPR pair to realize the protocol. Analysis results showed that this protocol not only ensures the security of the quantum key shared information, but also uses the entanglement states of two photons without unitary operation. And the protocol is simple and efficient.

By using the technique of integration within ordered product (IWOP) of operators, the time-evolution operator can be expressed as quantum image of the classical transformation in the coordinate and momentum phase space. The quantized mesoscopic RLC (resistance, capacitance and inductance) electric circuit and the corresponding Hamiltonian were obtained according to the way of the quantized mesoscopic LC electric circuit. By means of theoretical calculations, it was shown that there exists squeezing mechanism in the quantized mesoscopic RLC electric circuit. Furthermore, the concrete form of the squeezed state in the quantized mesoscopic RLC electric circuit was derived based on the IWOP technique and quantum Fresnel transformation.

In the process of transferring quantum information, it is repuired to reduce the number of particles as the quantum channel and maximize the transmission of information, while the safety and control of the transmission procession must be ensured. A scheme of multi-dimensional quantum superdense coding controlled transmission of information was proposed. At first, Alice and Bob should make a standard for information that would be encoded, then Alice does unitary transformation to particles, Bob measures the received particles and obtains the information that Alice wants to transfer according to the information of Charlie sending. This kind of information transmission requires less transform particles, so it is easier to accomplish. There is a controller to control the transmission process for the safty.

A generalized tripartite scheme is proposed for splitting an arbitrary two-qubit state by utilizing six-qubit non-maximally cluster states as quantum channel. It was shown that the splitter averagely partitions its unknown two-qubit state between two agents and either agent can recover the unknown state with the other agent’s assistance via appropriate unitary operation. A generalized Bell state measurement (GBM) and a single-particle measurement (SM) are needed in the scheme. In order to obtain the original state, an auxiliary particle was introduced and a suitable entangled match was selected. The probability of the successful quantum-information splitting (QIS) and classical communication cost was worked out. If the quantum channel consists of maximally state, the classical information consumes 14 bits, and the total probability of QIS equals to 1.

The dynamical properties of the population inversion of a trapped ion in standing wave field were studied by means of full quantum theory. The influences of the nonlinear parameter η and phase of the standing wave field φ on the collapses and revivals of the ionic inversion were discussed. The results show that the nonlinear parameter η has a great influence on ion population inversion, namely, when the parameter η increases, the period of ion population inversion becomes shorter and the oscillation frequency becomes larger. It is not obvious for contour of the collapses and revivals of the ion population inversion when η reaches a critical value. In addition, phase of the standing wave field also shows a significant influence on the ion population inversion, namely, when phase of the standing wave field φ increases, period of the ion population inversion becomes larger and the oscillation frequency becomes larger.

The temporal and spectral evolutions of the fundamental and second harmonic (SH) pulses were simulated in the propagation. By introducing the walk-off length and nonlinear length, the walk-off effect, group-velocity dispersion and cubic nonlinearity were described. The wavelength tuning characteristics of femtosecond-pulse second harmonic generation (SHG) were analyzed. It was found that the full width at half maximum (FWHM) of the SHG wavelength tuning curve of 40 fs pump pulses can reach as wide as 42 nm, while that of 40 ps pump pulses is only 2.8 nm.

Wavefront reconstruction is of great importance in adaptive optics. Accuracy of the reconstruction has a significant effect on performances of an adaptive optics system. An adaptive algorithm for wavefront reconstruction based on a reference-free Shack-Hartmann wavefront sensor is proposed. In this approach information needed for wavefront reconstruction, including the detection windows, the actual centroids, the reference centroids, and the reconstruction area, can be automatically determined according to characteristics of obtained spot field of Shack-Hartmann sensor. The effects of different reference centroids on the reconstruction result of the incident aberrations are discussed. The reconstruction algorithm is experimentally verified by compensating phase distortion produced by artificial atmospheric turbulence in laboratory through an adaptive optics system. The experimental results show that wavefront aberrations caused by the atmospheric turbulence can be reduced to below 0.1λ, which makes the quality of images close to the diffraction limit. The wavefront construction algorithm is an attractive and practical alternative to an adaptive optics system for telescopes.

In order to study the incoherently coupled spatial soliton pairs in open-circuit photorefractive polymer, the incoherently coupled dark-dark, bright-bright, grey-grey and bright-dark soliton pairs are predicted in open-circuit photovoltaic photorefractive polymer under steady-state conditions based on the polymer photorefractive effect. The results show that these soliton pairs can be established provided that the carrier beams share the same polarization,wavelength, and are mutually incoherent. When these incoherent coupled soliton pairs propagate together, two components can propagate stably in photovoltaic photorefractive polymer.

Investigation of millimeter wave stealth technology was implemented to improve ground target’s survivability in future battlefield under the threat of detection and guidance by passive millimeter wave. After considering the disadvantage of passive stealth, a new active stealth method was put forward based on the radiation characteristics of the target and background. Then, the theory of stealth method was analyzed, and the jamming power area density of different background under a typical bandwidth was obtained after the modeling calculation was processed. Finally, The stealth characteristics of the target were tested by outfield experiments. The experimental data shows that the radiant difference between the target and background is obviously depressed after jamming, and the technical feasibility of the stealth is also verified.

By using the adjustable spin filtering model, effect of the magnetic field and electron transition energy interval change on the spin electron filtering properties was calculated and discussed firstly. It’s found that the changing of the magnetic field and electron transition energy interval cause the electron tunneling probability and tunneling conductance to show the quantum step effect. As the magnetic field increasing, the electron cyclotron frequency and Zeeman energy levels splitting were strengthened at the same time. Then the transverse binding force was strengthened in the quantum point contact, while the spin filtering effect was weakened. When the magnetic field is given, the electron transition energy interval is smaller, and the spin filtering effect is much more obvious. Consequently, as the electron transition energy is changed, shape of the saddle-like potential and spin filtering sensitivity are changed too. For different materials, the role of both the magnetic field and electron transition energy interval were considered to find the best spin filtering result. More importantly, the quantum point contact structure can be easy acquired through the standard electron beam technique, so the results give the theoretical support for designing new spin filtering devices with application prospects and the potentially commercial value. Morover, if the spin filter substrate is fabricated by use of the high Landau factor materials, the spin filter performance can be further improved.

To eliminate the shortcomings of existing Quality of Service (QoS) mechanisms such as Preemption and Wavelength Partition (WP) in Optical Burst Switch (OBS) networks, an improved QoS based label switching path(LSP) sharing (QLS) algorithm was proposed. QLS algorithm supports statistical multiplexing of wavelength resource by improving the performance of low priority service while ensuring transmission reliability and validity of the high priority service simultaneously. An open source discrete event simulation software OMNeT ++ based OBS/GMPLS simulation platform was created for WP and QLS algorithm in 4×4 symmetric MESH network and NSFNET network topology. Simulation results shows that for class3 service, QLS algorithm can improve packet loss ratio by 0.2 and 0.3 for MESH and NSFNET, while average packet loss ratio performance improved 0.05 and 0.1 respectively.

Based on the Hamiltonian of carriers in bilayer graphene, characteristics of the guided modes in asymmetric quantum-well waveguides were investigated. There exist three different kinds of motions depending on the incident energy of the electrons and external potentials, i.e., quasi-classical motion, quantum Klein tunneling, and mixing of the former two. Given the wave functions for the different regions and using the continuity conditions at interfaces of the potential barriers, the dispersion relationship for the guided modes in asymmetric waveguides was derived analytically. Meanwhile, the structure feature of the guided modes under three different cases was discussed. The result is significant for the practical applications of graphene-based waveguide devices.