The oil fluorescence was measured by laser induced fluorescence (LIF) along with enhanced light excitation. The saturation effects in oil fluorescence spectroscopy were studied on two aspects, namely, the fluorescence intensity and spectral offset. In the experiment, it was shown that the intensity of fluorescence becomes to worse when the intensity of excitation pulse raises. The characteristics of fluorescence intensity at 430 nm in the linear and nonlinear ranges were derived through polynomial nonlinear curve fitting. Furthermore, the three-dimensional oil fluorescence spectra based on the excitation light energy were reconstructed according to the nonlinear fitting data derived from the fluorescence intensity in the detection wavelengths. The result demonstrated that the offset of oil fluorescence spectral peak and the nonlinear characteristics of the spectrum intensity with saturated excitation can be used to identify the oil samples which can not be distinguished by the general fluorescence spectroscopy.

The heavy metal elements in aerosol were harm to human health seriously, so it was necessary to in-situ and real-time monitor the heavy metals in atmosphere. Monitoring of aerosol by laser-induced breakdown spectroscopy (LIBS) system continued one month in South Central University for Nationalities. The distribution of PM10 and spectrum intensity of Be element was obtained in this month. The spectrum of heavy metal by fireworks combustion was obtained by using the monitor system. Qualitative analysis of heavy metal showed that the technology can detect several kinds of heavy metals in aerosol at the same time. Through quantitative analysis of simulated aerosol Cd, Sr, Na, Pb elements calibration curve were obtained. The linear correlation coefficient was more than 0.94. The results provide a new method for real-time online detection of heavy metals in atmospheric aerosol.

With a photoelectron source induced by ultraviolet radiation on mental surface, a photoemission ion mobility spectrometry (PE-IMS) was set up, which can be used to detect halide since halide has a good ability to attach electron. Using CCl4 sample, the evolutions of the ion intensity, full width at half maximum and resolution versus drift electric field, ion gate pulse width and ion gate voltage were obtained, and the reasons for the evolutions were analyzed simply. Taking into account both ion intensity and resolution, optimized experimental parameters were obtained. The PE-IMS has a limit of detection at 4 ppb for CCl4 and its measurable linear dynamics range is over two orders of magnitude in the optimized experimental parameters.

A new precise algorithm for computing the fitting coefficients of Zernike polynomial of human eye’s wave-front aberration was presented. The matrix of inconsistent equation group was triangulated by using improved Gram-Schmidt orthogonalization method. The Zernike coefficients were worked out directly. The algorithm was verified by fitting the given coefficients and normal mathematical surface respectively. The new algorithm has equivalent computational precision to the algorithm of constructing normal equation group. By avoiding constructing normal equation group, the computational error introduced by constructing normal equation group is eliminated. The new algorithm is easy to be programmed and proved to be an efficacious algorithm.

Using the concept of nonlinear self-adjointness and the general theorem on conservation laws developed by Ibragimov, nonlinear self-adjointness and conservation laws for the forced KdV equation are investigated. Its self-adjointness was disscussed firstly, and it’s found that the forced KdV equation is nonlinearly self-adjoint. At the same time, formal Lagrangian for the equation is obtained. Having performed Lie symmetry analysis for the equation, lots of nontrivial conservation laws for the equation were derived according to the difference of Lie symmetries.

LaLu0.7 Er0.3 O3 polycrystalline was synthesized by the co-precipitation method. It’s structure were determined by Rietveld refinement to X-ray powder diffraction, and the size of powder particles was also estimated. Its absorption and photoluminescence spectra at room temperature were measured. Under the excitation of 380 nm light, the 1.5 μm decay curve of Er3 + (4I
I15/2 ) was also measured, and the decay time was given. It’s shown that LaLu1-x Erx O3 is a potential infrared laser material, which has application value.

Synchronous realization of two magneto-optical traps is one of the fundamental technologies of testing Einstein’s equivalence principle by using atom interferometers. High frequency acousto-optic modulators were used to achieve the lasers for trapping 85Rb and 87Rb simoutaneously, and a dual magneto-optical trap of 85Rb and 87Rb was realized. Based on the dual magneto-optical trap, the dependence of atom numbers in the dual magneto-optical trap on parameters of cooling laser were investigated, and optimized experimental data were obtained. The number of both species reaches to 109 in the dual magneto-optical trap.

A scheme is proposed for the creation of cluster-type entangled coherent states via cavity QED. Based on the large detuning condition interaction between a three-level Λ type atom driven by two classical fields and two bimodal cavities, the spontaneous emission of the atom can be ignored. Moreover, the initial states of the two cavity fields are all prepared in vacuum. In this scheme, it is shown that the cluster-type entangled coherent states can be generated after the atomic measurement, and the experimental feasibility is also discussed.

Under different initial states, the time evolution of quantum state fidelity of C atom and H atom was discussed based on magnetic resonance force microscopy (MRFM) system. The results show that the time evolution curve of fidelity is different under the different conditions of initial states. Both deviation of the magnetic field due to the cantilever offset and interaction of spins and RF magnetic field make the period of fidelity decrease greatly. Consequently the quantum information can return its initial state in a short time interval. At the same time the RF magnetic field can make the quantum information approach ideal states in the transmission process that provides particular guidance for detecting atomic states in the sample and improving the accuracy of information in transmission process.

The evolutional characteristics of the atomic entanglement and optical-cavity entanglement were mainly investigated in the classical strongly driven cavity QED model, and two atoms are off-resonantly coupled with their cavity fields, respectively. By fixing the parameters of one atom and its coupled optical cavity field, and modifying the detuning between the other atom and its optical cavity, the occurrence area of the atomic entanglement sudden death was discussed, and the conditions on the emergence of the entangled coherent states between two optical cavity fields were acquired.

A scheme was proposed for implementing the entangled W state of three atoms trapped in distant cavities connected by single-mode fibers. The scheme is robust to atomic spontaneous decay, cavity decay and photon leaking out of the fiber due to that the atomic system, all the modes of cavity fields and fibers are only virtually excited. Compared to the previous schemes, the significant advantage is that the adiabatic passage is applied in the scheme. It does not need precise control of the Rabi frequency, pulse duration and is insensitive to moderate fluctuations of experimental parameters. In principle, the n-atom W state can be prepared by using such a method.

The system under consideration consists of a two-level atom coupled an optical field in k-photon Jaynes-Cummings model with a Kerr medium. The time evolution of field entropy squeezing and population inversion of the atom for three and four-photon transitions was discussed. The influence of Kerr medium on field entropy squeezing and population inversion of the atom was also analyzed. The results show that the field entropy squeezing and population inversion of the atom are sensitive to effect of Kerr medium.

The photonic band-gap characteristics of ten-fold quasi-periodic photonic crystal (QPC) are explored by using plane wave expansion method. The variation of the first band-gap is discussed with the dielectric constant and filling factor. It is found that there exists a linear relationship between the band-gap width and dielectric constant and there is an optimal filling factor. By comparing the band-gap of TE and TM mode, it is found that TM mode has a wider band. Furthermore, a comparison between ten-fold and eight-fold QPC proves that it is easier to produce band-gap for the ten-fold QPC.

The modes of electromagnetic surface waves sustained by the edge of a photonic crystal slab consisting of a honeycomb array of gyromagnetic material columns were investigated when an external dc magnetic field was applied to it. It is firstly demonstrated that in the photonic band structure of this photonic crystal slab, the original degeneracy point of the lowest two (photonic) energy curves can be lifted by applying an external magnetic field, thus forming a band gap between the two bands. Furthermore, it is demonstrated that based on this sort of band gap, surface mode sustained by the edge of the photonic crystal slab can propagate only in one direction, attributing to the time-reversal symmetry of the system broken by the external magnetic field. With the effective total internal reflection effect, the unidirectional edge mode in this three-dimensional system is confined in the direction normal to the photonic crystal slab.

According to single-photon quantum efficiency (SPQE) of single-photon avalanche photodiodes (SPADs), a strict mathematical model was proposed. The model is suitable for SPADs with In0.52 Al0.48 As or InP multiplication layer as well as In0.52 Al0.48 As-InP heterojunction multiplication layer for operating wavelengths of 1.3 μm and 1.5 μm. As the function of the device structure, operating voltage, and multiplication layers materials, the model can be used to optimize SPQE, furthermore evaluate and optimize the performance of APDs in Geiger mode.

Properties of the attenuated reflection and surface plasmon resonance (SPR) field distributions of both metallic and dielectric gratings placed on metal films were analyzed by using the rigorous coupled wave analysis. Relations between the gratings’ filling factors and the effective index(Neff) of the surface plasmon polaritons(SPPs) propagating on both structures were investigated. The results show that the increase of filling factor can only cause trivial changes to Neff of the SPPs on gold gratings, but distinct increments to that of the dielectric gratings.

An adaptive filtering algorithm for laser absorption spectroscopy was investigated. An improved measuring system scheme of laser absorption spectroscopy was proposed. Light beam emitted from laser was divided into three beams which constructed measurement channel, calibration channel and reference channel, respectively. Data acquisition circuit acquired signal data from three channels. Data from calibration channel was used for wavelength locking and concentration calibration. Signal data from reference channel contained noise associated with the measurement channel. Based on this, an adaptive noise canceller was constructed to reduce the effects of noise on measurement channel and improve the accuracy of the gas concentration inversion.

Within the framework of effective mass approximation, the binding energy of a hydrogenic donor impurity in Gax In1-x Asy P1-y stepped quantum wells (SQWs) is theoretically calculated using the variational method. The influence of applied electric fields and SQWs height on hydrogenic donor impurity electronic state is investigated. The results show that the hydrogen impurity binding energy reaches its maximum when the donor impurity is located at the center of the stepped quantum wells. The applied electric fields drive the electron wave function away from the stepped quantum well center, and induce asymmetric distribution of the donor binding energy in the SQWs. The variation of Ga and As content leads to the corresponding changes in the stepped quantum well height, which significantly affects the binding energy of hydrogenic impurities in the stepped quantum wells. The results are meaningful and can be applied in the design of optoelectronic devices based on stepped quantum wells.

The photoelectric signals of wireless optical communication transmit-receive system which used the intensity modulation direct detection (IM/DD) and on-off keying (OOK) were analyzed. Maximum a posteriori probability (MAP) method was performed to confirm the decision threshold. By employing lognormal distribution as the scintillation model in turbulence channel, the quantity relationship between system bit error rate (BER) and system factors such as turbulence intensity, source coherence parameter, optical power of laser transmitter, etc, was established. Adopting partially coherent light beam as signal source laser diminished the coherence and thus restrained the turbulence effect availably. The calculated results indicate that the behavior of system BER transforms 6 to 8 orders as turbulence intensity changes with a half order under some certain condition. Partially coherent beam with optimum coherence parameter, which can be acquired through computation, is most favorable for enhancing the communication system performance.

By using the transfer matrix method, phase properties of the transmitted light were studied from one-dimensional photonic crystal coupled-defect structure with the form as (HL)kA(LH)k containing N defects. It is found that for k=0, the transmitted phase curve is nearly linear. While for k≥1, the transmitted phase curve is stepwise and changes drastically around each transmitted peak with the corresponding phase-shift π or so. When introducing nonlinear materials, slight change of refractive index will result in a perfect π-phase-transition. Moreover, the transmittance is near zero at the π-phase-transition, which is helpful to reduce the influence by the dynamic chirp. Such phase properties hold great promise in designing various phase devices. Based on these properties, the sensitive all-optical switch and logic gate devices were designed as examples.