A high-speed data acquisition and processing system with integrated transceivers is designed to measure and monitor the wind fields at real time,which plays an important role in the multi-laser beam displacement measurement of wind field system. It can also realize the real-time extraction of low signal noise ratio (SNR) signals,which transforms rapidly in a wide dynamic range,spatial filtering,precision delay and accurate gate control technology. This system is mainly composed of YAG pulsed laser,avalanche photo diode (APD) detector,cascaded gain amplifiers,analog-to-digital conversion circuitry,field programmable gate array(FPGA) processing chip and its peripheral circuits,single-chip control systems and data transmission circuit. The experimental verification is also carried out,and the results show that multi-beam displacement measuring system can effectively detect the backscatter signals in various distances,by which we can calculate the wind speed and get the wind direction from data analysis.

A fiber Bragg grating (FBG) temperature sensor is presented. By setting bare grating support shelves,the temperature is measured with pressure isolation encapsulation. Multiple plus-minus temperature tests are carried out. Results show that the sensor under the condition of no press and the temperature of 35 ℃~85 ℃ has a good repeatability,hysteresis and linearity. The temperature sensitivity is 30.98 pm/℃ and the relative error is 0.3%,which is about 2.83 times of bare FBG. The accuracy is about 0.03 ℃. The pressure sensitivity tests are executed,and the results show that the sensor wavelength has no change under the condition of 35 ℃ and 5~45 MPa or the condition of 35 ℃ and 45 MPa. Moreover,compared the results under the condition of no press and 40 MPa,it is found that the sensor wavelength has no changes.

Under the condition of the framework of discrete fractional Fourier transform (DFRFT),the research on the phase retrieval problem of complex signals and images is reviewed. Firstly,based on the basic Gerchberg-Saxton (G-S) algorithm and the diversity of the DFRFT orders,a great number of numerical simulations are performed for the case of complex image and three DFRFT orders. The results indicate that when the difference of these orders is large,the two algorithms are quite efficient,and the whole performance of the serial version is better than the parallel one. Secondly,for the case of 1-D complex signal,an algorithm based on the non-linear least-squares is studied. This algorithm converts the original problem into the optimization of a non-linear least-squares,and then is solved by the Levenberg-Marquardt algorithm of Moré′s form. With two DFRFT amplitudes of arbitrary orders,the algorithm can reconstruct quite accurate phase distribution,and its performance for noisy amplitudes is also satisfying.

A fast inpainting algorithm of curvature driven diffusions (CDD) model is proposed. It is known that the curvature term requires a large number of iterations in solving the high order partial differential equation in original CDD model. Due to the success of the Split Bregman method in L1 regularization problem,it is introduced into the CDD model to speed up the algorithm. The experiments show that the new algorithm is much faster and has better vision effects than other similar methods.

The position of the point detector is one of the important parameters for the optical sectioning of the dual-axes confocal microscopy,so the point detector should be correctly positioned on the axis and without defocus. The effect of the point detector position in dual-axes confocal microscopy is analyzed. The results show that the slight axial offset of the point detector brings few effects on the axial intensity response,and a slight transverse offset of the point detector can introduce a shift into the axial response curve,while the main lobe of the axial response curve in shape is almost invariant,and the shift in the axis z increases as the offset increases.

The normalized space-dependent rate equations of the intracavity yellow Raman lasers are deduced,and the formulas of pulse energy and peak output power of the yellow laser are derived. The values of the composite variables are estimated from the reported experimental parameters. The numerical calculations are carried out to illustrate the effects of the composite variables on the performance of the intracavity yellow Raman lasers. The theoretical results from the new rate equations and the curves are compared with the experimental results,and it is shown that the theoretical study can predict the performance of intracavity yellow Raman lasers.

The in-situ WB-CrB reinforced Ni-based composite coating is synthesized by laser cladding on steel 45# by prior to pasting. The microstructure and phase analyses are performed by X-ray diffractometer (XRD),optical microscope,scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The microhardness and tribological properties of the coatings are also investigated. The results indicate that the coating epitaxial growing from the substrate with excellent bonding between the coating and substrate is ensured by the strong metallurgical interface. The microstructure at the bottom of the cladding layer mainly consists of orients dendrites of γ(NiFe). The microstructure at the middle and upper zones contains WB-CrB particles dispersed in the matrix of γ(NiFe). Compared with a pure Ni60 coating,the hardness of the WB-CrB complex particulate-reinforced composite coating is enhanced to HV0.31350. The wear and tear mass loss in a block on ring test against hardened steel is reduced by a factor of seven. This can be attributed to the presence of in-situ synthesized WB-CrB complex particles and their well distribution in the coating.

In order to monitor whether the light just passes the spatial filter pinhole center,an on-line detection method in compact space for large and complex laser system was designed. A prism is located close to the window of the spatial filter,so that the light from LED before CCD can be irradiated to the small hole. At the same time,the CCD can receive the image of reflected light,and thus on-line monitoring is achieved. The prism meets the required conditions,that the vertical distance between the prism cusp and the center of the hole is not less than 4 mm,and the angle of prism should be as small as possible so that the exit light is in parallel. Using the optical design software Zemax,the light path was simulated and the parameters of the prism were derived. The results show that the angle of the prism is 55°,and the right-angle side is respectively 10 mm and 14.3 mm. The experiment proves the feasibility and efficiency of the designed method.

In order to solve the problems in the alignment of the off-axis aspherical optical system,the relationship between system wavefront aberration and Zernike coefficient is investigated based on vector aberration theory. The model of off-axis paraboloidal mirror and misalignment optical system is built. By collecting interferograms of several fields of optical system by means of autocollimating interferometry,the Zernike coefficient of coma and astigmatism can be obtained from those interferograms. Compared with the coefficients calculated by the software,the changes of the Zernike coefficients are obtained and the misalignment values of the system are then calculated with the model. The feasibility of this model using the CODE V software is analyzed. The results demonstrate that the alignment scheme is feasible and guidable to the alignment of complex optical system.

A polarization converter based on cascaded transverse Pockels effect is presented. It consists of three lithium niobate crystals with external electric fields perpendicular to the light propagating direction. The refractive index ellipsoid theory and wave coupling theory for Pockels effect are employed to study the process of light propagating along the crystals. The study demonstrates that the polarization converter can transform an arbitrary polarized light to any desired polarized light by varying the three external electric fields. The examples to transform an arbitrary light to a linearly polarized light,a circularly polarized light and a desired elliptically polarized light are given.

A novel low-cost,small size variable fiber-optical attenuator (VFOA)device based on variable-focus microlens consisting of two kinds of liquids is put forward,whose basic structure includes a cylindrical precision tube sandwiched between two single-mode fibers (SMFs). Two kinds of immiscible liquids are placed inside the tube(water/oil/water),and constitute a thin liquid (oil) lens medium. The tube is made from electric conductor to acts as an electrode,and the other two electrodes are the right and left connectors connecting the conductive aqueous solution,respectively. The focal distance is tuned by changing the curvature of the meniscus through the effect of electro-wetting,so as to control SMFs coupling light intensity,and ultimately to achieve controlling optical attenuation. Theoretical analysis shows that the range of attenuation values of VFOA is 0~60 dB,and has a very good micro-loss characteristics of wavelength dependence.

The human eye is an imperfect refractive system which has not only defocus and astigmatism,but also spherical aberration,coma and anomalistic high-order aberration,all of which have influence on the imaging quality of retina. What′s worse,aberration is further enlarged as a result of mydriasis in dark field and weak light,thus making the vision performance of human eyes far below diffraction limitation. In recent years,the measuring technology of wavefront aberration of human eyes has got constant development,and the advanced measuring instruments for measurement of ocular aberration appeared soon after. The measurement instruments based on Hartmann-Shack (HS) sensor are very popular. The errors analysis of the measuring instrument based on Hartmann-Shack wavefront sensor is introduced. Then the new way to solve this problem is put forward.

The humidity sensors of existing technologies are described,and the use of laser scanning technology for humidity detecting new programs is proposed. By scanning the water in the absorption peak at 1.36 μm,a long-term stable detection of humidity is achieved,and the errors and drift can be avoided. The entire system with all-fiber design,achieves a long-range detection. As the probe and signal transmission do not require electricity,the system′s security features are enhanced. The system uses optical devices less susceptible to temperature and stress,making the system more stable even in the high temperature and pressure environment. The design of the humidity detection technology is described in detail,and a humidity detection system is achieved. It reaches the detection of 10-6 -level moisture.

With the development of THz technology,a lot of suggestions and concepts have been proposed to improve the imaging quality or extend the imaging dimensions in the field of THz imaging. Most of them are borrowed from the fully developed techniques in other wavelength ranges. The combination of these techniques and THz imaging has become a current research focus,and confocal THz scanning microscope is such a technique among them. Based on an introduction to the principle of confocal scanning microscope,a comprehensive description of the advances in the domestic and international research of confocal THz scanning microscope is provided,which illustrate the exciting potential uses for this emerging technique.

High power single frequency master oscillator fiber power amplifier is required for many applications such as coherent beam combination,gravitational wave sensors,free space optical communications,range finding,lidar and nonlinear frequency conversion. The progress of high power single frequency master oscillator fiber power amplifier is reviewed. The key techniques including seed source,stimulated Brillouin scattering suppression and amplified spontaneous emission suppression are analyzed in detail. The research trends of kilowatt levels single frequency master oscillator fiber power amplifier are pointed out.

Because of its high resolution,inherent optical sectioning and deep optical penetration,two-photon microscopy has been regarded as an excellent method for noninvasive detection. A potential clinical application of these microscopes based on optical fibers is their endoscopic use for optical biopsy of inner organs or brain of awake,behaving animals. The technology to build miniaturized fluorescence microendoscopes was reviewed. The different fibers used in two-photon microendoscope to propagate the excited laser and collect the fluorescence signal such as single mode,multi-mode and photonic crystal fibers were contrasted. Various scanning mode and system design were introduced. The research development and potential application were also discussed.

The current development situation of silicon quantum dots (QDs) solar cells is described. The multi-exciton phenomenon generated by the impact ionization due to the quantum confinement effect is introduced,and the silicon QDs cell design theory is analyzed. Meanwhile,several current production processes of the silicon quantum dots at present,and the detailed precipitation process of silicon quantum dots from silicon-rich silicon layers are presented. Finally,several kinds of configurations of the silicon QDs cells such as tandem solar cells,PN junction solar cells,and intermediate band-gap solar cells are introduced.

The progress in microoptics and the fabrication of special-shaped aperture microlens array are reviewed. Microoptics is produced on the fabrication of gradient-index lens. The rapid progress of microoptics is urged by the application of microlens array. A new domain of microoptics is founded by the fabrication of special-shaped aperture microlens array. The theoretical and experimental researches on special-shaped gradient-index lens and special-shaped aperture microlens array are mainly discussed and useful results are presented.

We model the natural dustlike particles by using mixtures of polydisperse,randomly oriented spheroids with varying aspect ratios. The rigorous T-matrix method was used to compute the single scattering of dustlike aerosols,and the result was compared with the spherical particle and single shaped spheroids. The results show that the phase function averaged over a wide aspect-ratio distribution of spheroids is smooth,featureless,and flat at the side-scattering angle and closely resembles those natural dustlike particles. Based on the vector radiative transfer theory,the multiple scattering characteristics of unpolarized light in dustlike aerosols are computed by the vector adding method with this model,and the result indicates that significant errors will be caused with the application of any single shaped particles to compute the scattering characteristics of dustlike particles.

The molecular mechanism of apoptosis induced by photodynamic therapy on human cervix cancer cells (HeLa) was studied. The method was to analyze the changes in FTIR spectrum of nucleic acids,proteins and lipids after photodynamic therapy. Compared with contrast group,the result shows that the peak intensity of the three spectrum lines (972,1083 and 1241 cm-1) representing nucleic acids decreases and the peak position shifts;the peak wave number of the spectrum lines (2923 cm-1 and 2957 cm-1) representing lipids increases and the peak intensity decreases noticeably;on the secondary structure of protein,the content of random coil and β turn increases dramatically and the content of α helix and β sheet decreases. It is concluded that photodynamic therapy leads to the damages of nucleic acids,proteins and lipids,as a result,inducing cancer cells apoptosis.

GaN thin films have been grown on Si(111) substrates by metal-organic chemical-vapour deposition. The analyses of X-ray diffraction indicate that GaN is of wurtzite structure with the 〈0001〉 crystal orientation. Raman spectroscopy is used to study the sample under different pressures. The results of Raman spectroscopy,show that when the sample is under relaxation,GaN flims are in tensile stress the maximum of which is 342.272 MPa and Si substrates are in compressive stress. But due to the existence of a buffer layer between GaN flims and Si substrates,the values of tensile and compressive stress are not identical. After applying different pressures parallel to the (0002) plane of GaN,the peaks of GaN and Si are both blue shit as the pressures increasing,which supports that applied pressures lead to compressive stress in the interior of the sample.