Compared to the accurate model of Faraday anomalous dispersion optical filter(FADOF), the energy level of strong field model is simple, so it can be used to give some analytical expressions. However, it is only valid when the magnetic field is strong enough. By solving transmission spectrum of the FADOF for sodium D2 transition by the two models, and testing these results by the experimental data, applying condition for the strong-field model is successfully found. When the magnetic field is less than 0.1 T, the transmission spectrum difference of the two models is greater than 50%, and when the magnetic field is greater than 0.3 T, the difference is less than 5%.

The construction and performance study is reported for a newly developed photoionization ion mobility spectrometer (UV-IMS) equipped with a 10.6 eV Kr lamp. The effect of the total voltage of drift tube, voltage and pulse width of ion gate on spectral resolution and sensitivity of UV-IMS were discussed. Their optimal values of pulse width, voltage of ion gate and drift tube are 0.15 ms, 80 V, and 2153 V respectively. The concentrations of benzene were prepared by means of exponential dilution method. The experiments show that the UV-IMS has a limit of detection at 400 ppt for benzene and its measurable linear dynamics range is over three orders of magnitude.

A multi-resolution multi-mode medical image registration method is proposed to improve the speed and accuracy of registration. The images were decomposed by wavelet function, and expanded Powell optimization algorithm was used to find the maximal mutual information (MMI) between images. The registration starts from the lowest-resolution image level 0 of the image pyramid, the deformation parameters of image level 0 registration are available as the initial parameters of image level 1, repeating the process until the completion of the highest-resolution image registration. The image registration results of CT/MRI and CT/PET show that wavelet-based multi-mode registration method has advantages such as avoiding local maxima, fast convergence and high accuracy.

By using the modified direct reduction method presented by Clarkson and Kruskal, the symmetry group theorem of symmetric regularized long wave (SRLW) equations are derived. Some new exact solutions of SRLW equations are obtained by applying the theorem and given solutions. Conservation laws of the equations are also obtained with the corresponding Lie symmetry.

Raman pulse sequences are generally used to coherently manipulate the atomic wave packet in an atom interferometer. High power Raman beams allow more atoms join in the velocity-sensitive stimulated Raman transition, and that will be helpful for obtaining high signal to noise ratio in atom interferometer fringe. Development of high power Raman laser is important for cold atom interferometer experiments. The experimental realization of high power Raman lasers are demonstrated based on injection locking technique. Master laser is modulated by a 1.5 GHz acousto-optical modulator, and the ±1 order diffraction lights are used as seeding Raman lasers. The seeding lasers are injection locked to two slave lasers which are further amplified as Raman beams. The frequency difference of Raman beams is 3.0 GHz, and the detuning range is about 200 MHz.

A new model was built for light propagation in two-dimensional anisotropic random medium, and the dielectric constant distribution was precisely described. The optical property of light waves in two-dimensional random media with uniaxial scattering particles was investigated by simultaneously solving Maxwell’s equations and rate equations of electronic population. Results show that ordered scatterers in anisotropic material can also form localization of light-waves if the index of refraction of the uniaxial scatterers distribute randomly in two-dimensional media. The randomness of rotation angle of the optic axis determines the index of refraction of each scattering particle and reinforces the random lasing in random media.

LiNbO3 crystal was widely used as high precision and high-speed switching shutters because of its features of wide wave band, fast response, non-easy deliquescence and so on. In order to expand exposure time of optical switching of LiNbO3 to nanosecond field so as to make up defects of extant high-speed optical switching, theoretical principles of LiNbO3 were explained as optical switching, and its aspect ratio for multi-band lights was optimized and the feasibility of LiNbO3 as a nanosecond optical switching was verified. Experimental half-wave voltages match theoretical values well. Experimental results also show that optical signal has synchronous response to electric signal. Results verify the feasibility of LiNbO3 as a nanosecond optical switching and provide theoretical and experimental foundations for the manufacturing of the optical switching.

Absorption and fluorescence spectra of Er:GSGG crystal were measured and investigated. The oscillator strength, spontaneous emission probability, energy level lifetime, emission branching ratio and absorption cross-section of Er3+ transitions were calculated according to the Judd-Ofelt theory. It is found that the crystal has long lifetime at 4I13/2 and 4I11/2, large absorption cross-section at 965 nm and 790 nm, large stimulated emission cross-section at 2.79 μm. Laser output characteristics were simulated numerically with 965 nm pumping, where it has a large quantum efficiency when the pump rate reaches certain value. The results show that the crystal may be a suitable laser material at 2.79 μm wave band.

In accordance with the high-performance and miniature requirement to pulse microwave source by the Ramsey-coherent population trapping (Ramsey-CPT) atomic frequency standard, a pulse microwave source, with the characteristics of high stability, high resolution, fast frequency hopping speed, low phase noise, miniature, and small scanning step, is realized through direct digital frequency synthesizer (DDS), exciting phase-locked loop (PLL) frequency synthesizer and then connecting the digital step attenuator and the impedance matching circuit. Several schemes of the pulse microwave source for Ramsey-CPT atomic frequency standard are compared. The basic principle and practical method of the pulse microwave source are introduced. The best performance of output signal is obtained by optimizing the simulation result. The pulse microwave source has excellent technical performance, and it further improves the output signal of the CPT atomic frequency standard. Moreover, the overall design comes up to the miniaturized requirement, and is favorable to portable application of the Ramsey-CPT atomic frequency standard.

Center-determination of laser spot is key to crown placement measurement system because it immediately concerns accuracy of the displacement. By using Matlab software, the grabbed laser spot image was smoothed with noise cancellation and median filtering to improve separating capacity of the targets and background, which set the terms for the object extraction. Then the image was segmented with Canny operator to extract target image from cluttered background. Finally, based on the extracted target, center coordinates of the laser spot can be found by using gray barycenter algorithm.

In quantum bit commitment (QBC), most existed proposals analyze little of communicating an innocent message over noisy quantum channels. These methods are not practical. Based on the information hiding characteristics of quantum steganography, a novel QBC protocal is proposed. An elegant scheme is presented for disguising secret information as quantum noise, and embedding it in stego qubits which encode into a codeword of quantum error-correcting code. The method is proved secure and effective in the presence of noisy quantum channel and it’s a potential eavesdropper. The results of theoretical analysis and numerical simulation show that the proposed scheme has perfect concealing and binding properties. Theoretical analysis proved the validity. The method forms a theoretical basis for the promotion and application of quantum cryptographic protocols.

A quantum signature scheme is proposed for multiple people signature situation. The digest of the classical message of any length is obtained via Hash function and transformed into quantum bits in the sender. Each signatory uses his private key XOR the digest and gets a sequence. The quantum bits are performed a controlled unitary transformation according to the sequence by the signatory in turn, and signature information is state of the quantum bits. A trusted arbitrator is presented to verify the signature. The progress of verification uses idea of classical parity. Analysis shows that the length of the signature doesn’t get longer with the number of signatory increased in the scheme. The communication efficiency is high, and the progress of verification is simple.

The generalized synchronization of different structure chaotic systems based on SETMOS with unknown parameters, double-scroll-like chaotic system and simple piecewise linear chaotic system is investigated with respect to an assumed function. By analyzing characteristics of the chaotic systems and definition of the generalized synchronization, based on Lyapnuov stability theorem, novel and simple adaptive controllers and corresponding parameter update law are proposed for generalized synchronization of different chaotic systems with unknown parameters. Further, if the function is changed, the theory can also be applied for other synchronization for different structure chaotic systems, such as adaptive generalized anti-synchronization. Numerical simulation results are provided to show the effectiveness and feasibility of the proposed theory.

Recent works show that amplification and compression of ultrashort fundamental solitons in a gain-distributed nonlinear fiber loop mirror can not only avoid pulse distortion caused by nonlinear effects such as self-phase modulation etc., but also overcome the difficulty of adiabatic amplification that the amplifier length must increase exponentially with the input pulse-width. Weak pulse amplification and compression in the gain-distributed nonlinear fiber loop mirror was investigated. Numerical results show that, as in the cases where the input pulses are fundamental solitons, distortion-free amplification and compression can also be realized when the input pulses have peak powers much lower than those of fundamental solitons, and that the amplified pulses are also close to fundamental solitons. The weaker the input pulse is, the larger the optimum gain of the loop mirror should be, and the higher-order effects have larger influences on the amplified pulses.

The nonlinear generalized Schr?倠dinger equation was applied to describe supercontinuum generation, whose evolution is simulated by numerical methods in the normal-dispersion regime of high nonlinear photonic crystal fibers (HN-PCFs). The effect of the pulse parameters such as the peak power of pump pulse, pulse width and the frequency chirp on characteristics of the supercontinuum spectrum was analyzed. The numerical simulations show that with the increase of peak power, the spectral width becomes wider and flatness of supercontinuum becomes better. With the increase of pulse width gradually, spectral width becomes narrower and the flatness of supercontinuum becomes worser. It is investigated that a broadband and flat supercontinuum was generated with proper positive and negative chirp pulse in transmitting along high nonlinear photonic crystal fiber.

Self-deflection characteristics of screening bright soliton in photorefractive crystal applied alternating electric field were discussed by perturbation method. This soliton is formed in the crystal when the direction of effective electric field of alternating electric field is along with crystal axis, while the self-deflection of the soliton orients the direction opposite crystal axis. Moreover, the deflection distance of the soliton center moving along a parabolic trajectory is proportional to the modulation degree of light intensity and third power of alternating electric field, respectively. It is worth to mention that this distance reaches maximum value for the ratio of center light intensity of soliton to the dark radiation intensity up to 10. Besides, the spatial frequencies of soliton center, along with self-deflection, transfer from the lower components of the spectrum into the higher components linearly, resulting in change for amplitude distribution of soliton in which the slope of the curve gets larger in deflection direction and smaller for the opposite.

Gold nanorods with multiple aspect ratios were prepared using seeded growth method. The refractive index sensitivity of nanorods was studied by monitoring the shift of localized surface plasmon resonance peak when the surrounding refractive index was changed. The experiment results show that sensitivity increases almost linearly with aspect ratio. It varies from 216 nm/RIU (aspect ratio 2.5:1) to 352 nm/RIU (aspect ratio 4.2:1) in the monitored wavelength range. Discrete dipole approximation (DDA) is performed to simulate the sensitivity of nanorod with aspect ratio 4.2:1, which is in accordance with the experiment results.

Partial least squares (PLS) cluster analysis, based on PLS regression procedure with a self-organizing mechanism, is a novel data analysis method of spectrum. PLS cluster was first used to classify simulated dataset, and present the general properties and validity. Then it was used to aerosol laser time-of-flight mass spectra data, showing correctness and successful application in practice. Finally, this method was applied to mixed spectra dataset of aerosol particles of CaCl2, MgCl2, NaCl and KCl. By examing the statistical properties of obtained dendrogram plots and nodes, the reason of clustering and misclassifying was obtained. It demonstrates the application potential of PLS-Cluster in individual aerosol particle spectra.

The polarization properties and propagation characteristics of polymer photonic crystal fibers with elliptical air-holes and hexagonal structure are investigated by using the full vectorial plane wave method. The results show that birefringence of the fiber is induced by asymmetries of cladding. Moreover, by adjusting the elliptical ratio of cladding, the optimized design parameters of fiber with birefringence were found, operating in a single mode regime at an appropriate wavelength range. The range of wavelength is consistent with the communication windows of polymer optical fibers. With elliptical ratio of cladding η=2.5, the fiber is able to exhibit high birefringence of 4.8×10-2. The conclusion is useful for preparing high birefringence polymer photonic crystal fibers.