Based on femtosecond photoeletron imaging technique and time-of-flight mass spectroscopy, the photoionization/photodissociation mechanisms of allyl chloride (C3H5Cl) at 200, 400, 800 nm femtosecond laser pulses are investigated. Results show that the photoionization/photodissociation mechanisms of C3H5Cl have dependence on laser wavelength. At short wavelength 200 nm, two-photon ionization is the dominant channel of parent molecule C3H5Cl, and other fragment ions are generated by dissociation of C3H5Cl+. When it shifts to longer wavelength, such as 800 nm, dissociation from intermediate states of C3H5Cl starts to play a leading role, and the signals of fragment ions are also enhanced. Photoelectron spectra further confirm that there are photoelectrons coming from neutral fragments at 400 nm and 800 nm, and they are generated from dissociation of the intermediate states of C3H5Cl. It implies that at 400 nm and 800 nm, the parent molecule may be excited to intermediate dissociation states with shorter life-time and produce neutral fragments, which makes the process of light dissociation play an important role in the long waveband.

An identification method of terahertz (THz) spectra of biomolecules is proposed based on principal component analysis (PCA) and fuzzy pattern recognition, and THz spectra of several typical saccharide and amino acid biomolecules are used to verify its effectiveness and feasibility. PCA is used to decrease the dimensionality of original THz spectra variables and extract data features. Instead of the initial THz spectra variables, the selected principal component score matrix is input into the model of fuzzy pattern recognition, and fuzzy recognition based on principle of fuzzy closeness optimization is employed successfully to identify these samples. Results show that using THz spectroscopy of biological molecules as data feature, it is feasible to realize the detection and identification of biological molecules by the combination of PCA and fuzzy recognition. It provides a new and effective analytical method for the identification and recognition of biomolecules by using THz spectroscopy.

In order to accurately extract the phase of the measured object in a vibrating environment, a phase extraction algorithm based on double time domain Fourier transform is proposed. A time domain light intensity signal with two interference periods is divided into several sub-segments with one period. The phase shift frequency introduced by phase shifter and other interference frequencies are separated by carrying out Fourier transform twice. Simulation and experimental results show that the algorithm significantly improves the system’s ability to resist interference under the premise of not improving the system complexity and greatly reducing the data acquisition amount. Compared with the traditional four step phase shift algorithm under the ideal condition, the root mean square error of the measurement can reach 0.062 rad. The proposed method is without manual intervention from acquisition to phase extraction of the measured object, which is conducive to the realization of automation.

Based on the single pixel imaging theory realized by acquisiting Fourier spectra, a single-pixel lensless imaging method is proposed by loading a series of gray stripes on a liquid crystal display (LCD) screen and placing a single pixel photoelectric detector in front of it to receive the light projected by an object. The imaging system reduces the requirements for hardware, has compact optical path and strong flexibility. It is verified theoretically that the nonlinearity between the gray scale of the image loaded on LCD and the intensity of transmitted light has no influence on reconstructed images. The effectiveness of the imaging method is confirmed experimentally. Experimental results show that after loading the stripe, it’s needed to set aside certain response time, so that the detector is able to obtain accurate light intensity. Background noise and interference of conjugate image are significantly reduced and the reconstructed image quality is improved.

In order to reduce the probability of traffic accidents caused by night driving, and provide initiative safety system for vehicles in poor visibility environment, according to the basic requirements of auxiliary driving system, a nighttime pedestrian auxiliary model is designed based on far infrared sensor technology. The model captures the original data source by far infrared sensors. Regions of interest (ROIs) are obtained using gray statistical technique. Multi-scale probability template is constructed, and the data source is matched and detected. The detection rate and missing rate of the model are further improved by multi-frame checksum integrated processing technology. Experiment results show that compared to the common methods, the matching accuracy of probability template of the model is greatly improved. It can be used in the suburbs and urban traffic conditions, and its practicability is good.

In view of the high resolution remote sensing image with multi-scale, complex spatial distribution and the characteristics of a wide range of features, the method of high resolution remote sensing image classification is proposed based on multi-scale and multi-feature fusion, which is starting with the scale effect of feature extraction from remote sensing image and various conspicuousness of different objects. The optimal segmentation scale function is constructed using the method. The optimal scales of different objects are obtained, and texture, color and shape features are extracted respectively. The multi-scale and multi-feature weighted fusion is realized by using significant differences of different objects in characteristics. The weighted fusion method breaks through the limitation of the conventional optimal scale segmentation algorithm, which fails to fully consider the diversity of all kinds of features of different objects. By analyzing the significance of all kinds of features, a model is established based on the weight of each feature. Experimental results show that the accuracy of this method is increased by about 7% compared with that of the traditional unsupervised classification algorithms, and the operation efficiency is high.

Aiming at the problem of too much perceptual distortion and high error rates caused by high image source compression rate existing in steganography technology of information security field, an image steganography based on Karhunen-Loeve transform (KLT) optimization technique is designed. The covariance matrix and cluster mean value are obtained with iterative clustering algorithm. It divides images by adjusting the correlation values. The image data are compressed by introducing KLT algorithm. The least significant bit is adopted to hide data instead of the encrypting data. Image informations are hidden effectively by using inverse linear transformation operations and the original pixel matrix when extracting informations. Results show that image extracted by the method has higher capacity, larger signal-to-noise ratio and smaller image data distortion compared with common algorithms.

A Linnik type full-field optical coherence tomography (FF-OCT) system is developed for tomographic imaging of biological cells. Different from other imaging methods used in FF-OCT systems, an image restoration method based on Hilbert transform is adopted, which requires only two interference images to recover the structure information of the sample. Even if the phase shift error occurs, the sample chromatogram can still be obtained. The measured longitudinal and lateral resolutions of the system reach 1.1 μm and 2.5 μm, respectively. Feasibility of the FF-OCT system is verified by preliminary imaging experiments of onion epidermal cells, and it lays foundation for the further realization of high resolution cell imaging.

Exact solutions of (3+1)-dimensional Jimbo-Miwa equation and nonlinear transmission line potential equation are obtained with improved trial function method, including hyperbolic function and trigonometric function solutions. When parameters in hyperbolic function solutions are taken as some special values, the solitary wave solutions can be obtained. When parameters in trigonometric function solutions are taken as some special values, the periodic wave function solutions can be obtained. Practice proves that the trial function method is widely used in the field of nonlinear mathematical physics equations.

A switchable high power dual-wavelength self-similar parabolic pulse laser is proposed based on normal dispersion single-mode fiber, Yb3+ doped gain fiber and multimode fiber Bragg grating. The transmission and evolution of dual-wavelength self-similar parabolic pulse are simulated numerically by split-step Fourier method with the nonlinear Schrdinger equations. The input pulses produce self-similar parabolic pulses in normal dispersion single-mode fiber and Yb3+ doped gain fiber. The dual-wavelength selection is carried out by a multimode fiber Bragg grating for laser. The dual-wavelength stable operation is realized by adjusting the polarization controller. Numerical simulation shows that the operation of the laser is feasible and effective.

The first-order spatial coherence of ultracold Bose gas above the phase transition temperature in static-magnetic trap is investigated by using phase grating produced by one dimensional optical standing wave field. The interference patterns of thermal atoms are calculated in theory, and the interference patterns of ultracold atomic gas above the phase transition temperature are also obtained by experiments. By comparing the contrast of interference patterns of atomic gas in theory and experiment, it’s found that when the temperature of ultracold atomic gas is very close to the phase transition temperature, coherence of the atomic gas is better than that of thermal atom. With increasing of temperature, the coherence of atomic gas decreases gradually, and it is the same as that of thermal atom finally.

Josephson mixer is a kind of circuit which can generate entangled quantum microwave signals. An equivalent circuit model of Josephson mixer is established. Quantization is carried out on three-wave mixing Hamiltonian. Influences of the critical current of Josephson junction, shunt linear inductance, equivalent inductance of resonator transmission line and applied effect of flux through the ring on three-wave mixing intensity are investigated. Simulation results show that the critical current of Josephson junction determines the maximum value of the chosen linear inductance, but has little influence on three-wave mixing intensity. The value of linear inductor determines the optimal value of flux through the ring and maximum value of three-wave mixing intensity. Resonator transmission line equivalent inductance is the smaller the better in the allowable range. It is of great value to choose circuit component parameters effectively and improve the generating ability of entangled quantum microwave.

The unitary transformation matrices of nodes expansion are analyzed by using quantum computing method for 3-puzzle problem. Element coding and node state coding are performed on a 3-puzzle problem instance. The specific node expansion unitary transformation matrices are described, and the unitary transformation matrices are realized by using the quantum controlled-NOT gate logic circuits. A logic circuit model of N-puzzle quantum computing is discussed. The preparation of ground state and optimum ground state of quabits is analyzed, and the N-puzzle heuristic search quantum computing framework is discussed.

Effective manipulation on the state of the charge qubit system consisting of Josephson junctions by means of Lyapunov control theory is performed. Numerical simulations show that the manipulation on superconducting qubit system can be realized via choosing proper control amplitude whether directly or indirectly using the deviation based on Lyapunov method. Quantum system can be controlled by selecting the appropriate control range. The bigger the control amplitude is, the smoother the control function curve is, and the shorter the control task time is. This control method can avoid the interative calculation of complex traditional control methods, and ensure the stability of quantum system. Therefore Lyapunov method is a kind of practical manipulation method.

In order to investigate noise perturbation in self-similar pulse system, the variance formulae of timing and energy jitter are derived from the nonlinear Schrdinger equation with noise. Results show that the noise greatly distorts self-similar parabolic pulse shape, optical spectrum and chirp, and noise perturbation leads to pulse oscillation and frequency spectrum jitter. The pulse still has a linear chirp, but appears fluctuation at the front and back edges. The noise disturbance is very small and can be ignored in the initial stage, and the influence of noise disturbance increases rapidly with increasing of transmission distance. The influences of different dispersion and gain on time and energy jitter variances are different.

Laser shock is a new surface modification technology for metal material by irradiating them with high power pulsed laser. The laser shock contrast experiments are carried out on three typical metallic structural materials, aluminum, titanium and stainless steel with water bound layer and mark pen coating as protective layer. The damage characteristics of the three metallic structural materials are obtained under high laser shock, and the relationship between the number of laser shock and pit depth on the metal samples is analyzed quantitatively. Results show that the dent depth and impact times show a linear relationship, and the slope is inversely proportional to the yield strength of metal materials. To explore the effect of laser shock spot morphology on metallic material damage, the impact situation of square and circular spots are compared. Test data show that the surface damage morphology of the specimen is consistent with the spot, and damage caused by the circular spot is more serious.

An optical film used for spectrum monitoring in facility agriculture is designed. Three kinds of optical films used in facility agricultural, red light filter, blue light filter, red and blue light filter are obtained by the combination of cut-off filters. Center wavelengths of red light and blue light are at 460 nm and 660 nm, respectively, and the transmission bandwidth is about 50 nm. The light transmission bands of red light and blue light are set according to demands of the plant to spectrum. In practical application, the center wavelength and bandwidth of light transmission can be set as needed. The filters can be used to make spectrum monitoring cells used in facility agriculture and agricultural research. The specific optical film is placed on the silicon photovoltaic chip, and light intensity of the optical panel preset band is monitored by measuring the power of the photovoltaic chip.

Based on one dimensional high-order nonlinear wave model, the possibility and existence condition of kink and anti-kink solitary waves in microstructured solids are analyzed with the qualitative analysis method of dynamic system. Analysis results show that the kink and anti-kink solitary waves can exist in high-order nonlinear and anomalous dispersion microstructured solids under appropriate conditions, and the existence conditions are given exactly. Influences of high-order microscale nonlinear effect on the kink and anti-kink solitary waves are analyzed with the numerical method. Results show that the kink and anti-kink solitary waves become more and more steep (or gentle) with the negative reinforcing (or positive reinforcing) of high-order microscale nonlinear effect, while their amplitudes remain unchanged.