The photodissociation mechanism of long-chain alkyl iodides and cyclic alkyl iodides at 267 nm were studied using ion velocity imaging technique. Speed and angular distributions of corresponding photofragments were obtained by detecting ion images of I*(5p2P1/2) and I(5p2P3/2). Relative quantum yields ф(I) and ф(I*) were also obtained. Iodine fragments in this study were both produced via direct and rapid dissociation of C-I bond after absorbing one photon of 267 nm. Compared to long-chain alkyl iodides, cyclic alkyl iodides have obviously different characteristics of angular distributions which the value of anisotropy parameter β for I is bigger than that for I*. And as the alkyl group becomes heavier, ф(I*) tends to decrease.

Rb vapor was irradiated in a glass fluorescence cell with pulses of radiation from a YAG laser-pumped OPO laser, populating 5Dj (or 7S ) state by two-photon absorption. Energy transfer in Rb (5Dj,7S)+Rb(5S) collision is studied using methods of atomic fluorescence. The resulting fluorescence includes a direct component emitted in the optically excited state decay and a sensitized component arsing from the collisional populated state. At the different densities of the components, fitting a three-state rate equation model, the cross section σ=(3.7±0.9)×10ˉ14 cm2 was obtained for Rb (5D5/2)→Rb(5D3/2) transfer. The cross section for excitation transfer out of the 5Dj doublet are (3.1±1.2)×10ˉ14 cm2 (for j=5/2) and (2.0±0.6)×10ˉ14 cm2 (for j=3/2), respectively. The energy transfer cross section for the Rb (5D)→Rb(7S) is small, (1.6±0.4)×10ˉ16 cm2. The 5Dj state is quenched mainly in the reverse energy pooling processes, i.e. Rb(5Dj)+Rb(5S)→Rb(5P)+ Rb(5P).

A novel method measuring the Stokes elements spectral was proposed. The main idea of the method is that a modulator consisted by two retards and one polarizer is placed before the spectrometer and let the light under test go through the modulator to the spectrometer. Measuring the power spectral from the modulator only one time and executing the demodulation algorithm, the whole Stokes elements spectral from the light under test can be obtained. The disadvantages of the old methods can be removed completely by the new method. The principle for measuring the Stokes elements spectral based on the new method is deduced in detail and its feasibility is proved by the numerical simulation.

An image reconstruction approach for near-infrared optical tomography (NIR OT) based on a parallel neural network is presented. The parallel BP neural network is used to distinguish the nonlinear relationship between the spatial location of tumor and light intensity around the boundary of tissue. The method turns a complicated model into two simpler ones to build two parallel BP neural networks. The steady state diffusion equation of the two simple models is solved by Femlab software. The inverse problem is solved as optimization problem by Levenberg-Marquardt algorithm. The concept of the average optical coefficient is proposed, which is helpful to understand the distribution of the scattering photon from tumor. The reconstruction can be obtained by the trained network. The fast reconstruction of tissue optical properties and provided reconstruction of OT with a new method can be realized by proposed algorithm.

The auxiliary equation of the triangle function type and its solutions are given. The equation is directly applied to sine-Gordon equation, double sine-Gordon and MKdV sine-Gordon, with the help of symbolic computation system Mathematica. The Jacobi elliptic function exact solutions, degenerated solitary wave solutions and triangle function wave solutions of the equations are obtained.

The longitudinal discharge-excited Ca+ recombination laser operating at 373.7 nm/370.6 nm was studied for the practical purpose. A simple model of temperature field was presented for the Ca+ recombination laser discharge tube. An analytical expression of the radial temperature distribution in the tube was given. The relation among radial temperature distribution, output power restriction and thermal conductivity of the buffer gas was described. Good agreement exists between the calculated and measured results. This physical analysis can be applied to design Ca+ recombination laser.

From the concept of radiation force, the friction and diffusion coefficients are given, then the cooling temperatures are analyzed using the Einstein relation. It is shown that temperatures much lower than the Doppler limit can be achieved, and the two-photon laser cooling scheme is more efficient than the one-photon laser cooling. It provides theoretical basis for experimental research.

The entanglement of two coupling spin 1/2 particles induced by outside magnetic field was studied under Heisenberg picture. By solving the differential equation group of systemic polarization vector varying with time using numerical method, the rule of polarization vector varying with time was obtained. Calculation results reveal that the un-entangled state of two coupling parallel spin 1/2 particles with total polarized vector z component being -2 could translate to entangled state under suitable outside magnetic field condition. The best parameters of outside magnetic field were obtained, and a new method was put forward to judge whether the system of two coupling spin 1/2 particles was in entangled state based on the change of polarization vector with time. This method wasn’t built upon adiabatic approximation, and it is suitable for more complicated situations, such as systems with relaxation.

A scheme is proposed to implement quantum controlled-not (CNOT) gates with a resonant cavity and this quantum gate is used to carry out teleportation of an arbitrary single-atom superposition state. By using three level atoms, it can be realized through single-qubit operation and resonant interaction between two atoms and a resonant cavity. The interaction time between two atoms and the single-mode cavity is very short, which is important in view of decoherence. This character is one of the advantages of this scheme comparing to the scheme based on detuned cavity.

The construction energy matrix and characters of the matrixs are introduced when different electron spin exchange in the sites of Heisenberg chain in one dimension. There are three situations that the sites of Heisenberg chain are filled with single electron only, two electrons only, or single and two electrons at the same time. The exchanges of electron spin of the nearest neighbor site are classified into two sorts. The first sort is the exchange of the nearest electron spin. The second sort is the exchange between the left and the left (or the right and the right) electron spin. The Hamiltonian operator of system of Heisenberg chain acts on the complete basis vectors produced with permutation group to form energy matrix. The calculating results are the following. (1)When the sites are filled with single, two electrons and them at the same time, the matrixs of [4,2] are different except for the sites filled with symmetrica election spin. (2)When the sites are filled with two electrons, the matrixs of [4,2] formed in the second sort are different from that in the first sort except for the sites filled with symmetrica election spin. The same Hamiltonian operator acts on the same complete basis vectors to produce same or different matrixs contrast the exchange between the left and the left neighbor electron spin to the exchange between the right and the right neighbor electron spin. Finally, the rules of the matrixs and their studying significance are showed.

The entanglement dynamics of two entangled two-level atoms interacting with a coherent light field is investigated by means of the standard of entanglement concurrence. The influences of the coupling coefficient of Stark effect on the entanglement dynamics of the system are discussed. The calculating results show that the time evolution of two-atom entanglement is influenced by the coupling coefficient of Stark effect. The time evolution of two-atom entanglement displays periodic entanglement and disentanglement when the coupling coefficient of Stark effect is much smaller, while the disentanglement will disappear when the coupling coefficient of Stark effect is much larger. That is to say, the statement of entanglement can be preserved preferably.

The evolution characteristics of the fidelity of quantum states for a V-type three-level atom interacting with the two-mode odd-even entangled coherent field are investigated. The influences of the detuning parameter, the two-mode light field intensity and the atomic distribution angle on the fidelity of quantum states are discussed by using numerical calculation. The results show that the nature of fidelity for the atom is better than that for the system and the field, the increasing of the detuning parameter or the initial field intensity can be a good help for increasing of the fidelity of the atom, and it is much better when the atom is initially in the ground state. The evolution frequencies of the fidelities are modulated by the detuning parameter. The quantum collapse and revival behaviors occur when the two-mode light field intensity is strong enough.

The atomic dipole amplitude-squared squeezing characteristics of a Ξ-type three-level atom interacting with the binomial states field were studied by solving Schr?dinger equation and numerical calculation. The effects of the optical field parameter, the field-mode speed, the η-parameter, and the optical field and atomic coupling coefficient on the atomic dipole amplitude-squared squeezing characteristics were analyzed. The results indicate that, with the optical field parameter increasing, the atomic dipole amplitude-squared waries from having no compresses to presenting the periodic squeezing, and the squeezing depth deepens gradually. With the field-mold speed increasing, the atomic dipole amplitude-squared changes from squeezing incompletely to completely. With the η-parameter increasing, the atomic dipole amplitude-squared varies from no compress to the periodic squeezing, finally to squeezing. The optical field and the atomic coupling coefficient do not affect an atomic dipole amplitude square squeezing.

Using number-phase quantization scheme, mesoscopic LC circuit is quantized to one dimensional harmonic oscillator coupled to a thermal field. The Wigner function of the free thermal state is obtained by using the coherent state representation and normal product form of operators, and then the quantum effects of charge number and phase-difference in free thermal state are discussed by using Weyl-Wigner correspondence. It is found that, the quantum fluctuations of charge number and phase-difference in free thermal state are related to not only the parameters of the circuit, but also the temperature, and the average energy stored in the capacitance and inductance is equal to each other. It is proven that the number-phase quantization is very useful to tackle with quantization of some mesoscopic circuits and the quantum effects.

The omnidirectional reflection properties of one-dimensional photonic crystals are studied by using the bandgap theory deduced by the transfer matrix method. Investigations show that the constructure parameters affect the omnidirectional reflectivity band of a photonic crystal significantly. In order to increase the omnidirectional reflectivity band, some methods are proposed to increase the refractive index of dielectrics, the ratio of the high and low refractive index, and make the ratio of the optical thickness near to 0.85. The conclusion is helpful for designing a dielectric omnidirectional reflector.

The light wave propagation in quasiperiodic one-dimensional photonic crystals with the doped defect and the substitutional defect is studied by means of the transfer-matrix method. The results show that defect modes appear in the bandgaps of this kind of quasiperiodic one-dimensional photonic crystals with defect, similar to the traditional periodic structure photonic crystals with defect. The defect modes caused by the doped defect and the substitutional defect are similar to each other. The defect modes broaden the bandgaps and the characteristics of defect modes are greatly related with the position and optical thickness of the defect. The wavelength of defect modes shifts in the direction of long-wavelength with increasing of the optical thickness of the defect layer.

Based on the generalized nonlinear equation of negative refractive media, the self-phase modulation chirp, self-steepening chirp, fake-quintic nonlinearity chirp, second-order nonlinear dispersion chirp and total chirps induced by all nonlinear effects are simulated by using the split-step Fourier method. The results show that the center of the pulse can shift both the leading edge and the trailing edge because the parameter of self-steepening can be negative and positive. In normal dispersion area, the fake-quintic nonlinearity leads to the broadening of pulse if the parameter of fake- quintic nonlinearity is negative, the second-order nonlinear dispersion leads to the broadening of pulse if the parameter of second-order nonlinear dispersion is positive and the compression of pulse if the parameter is negative.

In the research of induced focusing of a beam in self-defocusing media, two-dimensional theoretical model can agree with the three-dimensional experimental results only qualitatively. And there is no three-dimensional theoretical model that can describe the experimental phenomena quantificationally up to now. The transmission of two beams with an angle in the three-dimensional media is discussed. Exactitude derivation of three-dimensional coupled equations is given, and it is found that the description of the beam transmission in this situation is related with the Cauchy problem of the nonlinear coupled equations and the initial conditions of the linear “chatter” phase. The simulative results based on the three-dimensional theoretical model agree with the experimental results quantificationally.

Two-pump fiber optical parametric amplifier (FOPA) with two-section highly nonlinear fibers is proposed and demonstrated, which has broad bandwidth, high and flat gain. Using the fourth-order dispersion coefficient of the fibers as a pivotal factor, the optimization of the gain characteristics of the FOPA with double pumps and two section fibers is achieved. The FOPA with 424 nm bandwidth, 62.46 dB average gain and gain ripple less than 5 dB is obtained.

For 351 nm XeF excimer, an illumination system for PCB laser projection image used for high resolution, high throughput, large area and conventional photoresists exposure is designed. On the basis of the theory model of the excimer’s partly coherent flat-top Gaussian beam (PCFGB), the diffractive characteristic of micro-lens array (MLA) homogenizer is theoretically analyzed. The uniformity of MLA homogenizer influenced by the diffractive effect is quantitatively analyzed by means of distribution of PCFGB, diffractive angles of constant intensity and Fresnel-Kirchhoff diffractive integral formula. The theoretical calculation indicates that the amplitude is modulated not only by Fresnel diffraction at the microlenses edges but also by multiple beam interference, and it is just obvious that the spikes produced by diffraction emerge in the beam edges. Meanwhile, for the PCFGB curves obtained by numerical integral, it is found that 9×9 MLA homogenizer can ensure the overlapping uniformity of the beams from individual microlenses and decrease the effect of the diffraction and multiple beam interference to a great extent. By way of using a hexagonal diaphragm, the spikes at the beam edges produced by diffraction can be cut down and the large-area seamless scanning lithography met. Using ZEMAX optical design software to simulate the effect, it shows that the process window is less than ±2%。

The thermal effect of metal spherical shell irradiated by invariable power density laser was calculated using finite element method. The variety rule for temperature rise and temperature difference of inwall and outerwall was analyzed, also the metals of copper and aluminum were taken for example, and the temperature variety and response time of the copper spherical shell irradiated by laser were compared with the aluminum spherical shell. The results indicate that, when the transitional process finishes, the temperature rising speed of inwall and outerwall is almost a constant, and the temperature difference of inwall and outerwall keeps constant during laser irradiation. When the laser irradiation stops, the heat balance process between inwall and outerwall will be done within tens of milliseconds to one second for the copper and aluminum spherical shell with thickness from 0.004 m to 0.02 m.

Based on coherent optical communication theory, experimental setup was designed to build a homodyne coherent optical detection system platform. PCI6111E from National Instruments corporation is used as a data acquisition module for its high performance. The sender and receiver control software on different computers were designed under virtual instrument environment LabVIEW. Experimental results show that by use of light-synchronization and LabVIEW software control, acousto-optic modulator, electro-optical modulator of sender, data acquisition of receiver and phase regulator based on piezoelectric ceramic can work together in cooperation, and coherent optical information modulation on sender and real-time demodulation on receiver are realized.

ASE broadband light source based on erbium-doped fiber (EDF), as an excellent broadband light source, has attracted much attention. The output spectral characteristics of ASE broadband light source based on EDF with single- and double-pass configurations are respectively investigated experimentally. With the central pump wavelength of 1480 nm, the influences of EDF length and pump power on output spectral width and flatness are studied for both the single- and double-pass configuration ASE sources. It is found that the power of ASE source located in the L-band, especially in the wavelength range of 1570~1620 nm, for the double-pass configuration may be enhanced, giving a wider and flatter spectrum in whole C- and L-bands by comparing to the output spectra for the single-pass configuration. All the experimental results will be helpful for the developments of ASE broadband light source.

The total internal reflection-photonic crystal fibers (TIR-PCF) are proposed by filling the air hole of solid-core PCF clad with nematic liquid crystal which the refractive index is less than that of background glass within the temperature and wavelength in research. The effective index of clad with filled liquid crystal is put out by the fundamental space filling mode index. The temperature sensor properties in the PCF are studied by the step effective index model, and numerical calculation is carried out. The results show that the effective index of clad and equivalent core radius increase with temperature increasing, and increase quickly about clear point of liquid crystal. The cutoff wavelength of the second mode decrease with temperature increasing, and decrease quickly about clear point of liquid crystal in the PCF infiltrated with liquid crystal.