Considering the shortcomings of the existing long distance coherent optical communication receiving system using single tube detectors which receives weak signals with large noise and low SNR, a balanced detector is designed for coherent optical communication system. The balanced detector uses two diodes with TIA respectively and reduces most of the laser′ s relative intensity noise after two hybrid magic Tee′ s coupling and subtraction. The coherent optical system is set up to test the performance of the balanced detector. The local-oscillator and signal laser are mixed and then the eye diagram shows that communication is in good condition. By comparing the spectrum, the results show that the noise of the coherent optical communication system is reduced by using the balance detector compared to the single tube. The signal-to-noise ratio of system is enhanced about 10 dB, which proves the balance detector′s feasibility and superiority for application in the coherent optical communication system.

The semiconductor optical amplifier (SOA) is the key device for all optical signal processing, and the principle mechanism is its nonlinearity, which heavily depends on its group velocity dispersion (GVD). Based on the Kramers-Kronig relation, the relationship between GVD and the optical gain is obtained. A simple scheme to measure the GVD of the SOA is proposed with some computations from the measured gain spectra, and it is verified with the comparison between the analytical simulations and the measurements under the condition of small signal input. The dispersion is relatively flat in the range of 1530~1610 nm, and lightly depends on the input power and the injection current. The peak-gain wavelength and zero-dispersion wavelength red-shift with the input power increasing and blue-shift with the injection current increasing, and the zero-dispersion wavelength is greater than the peak-gain wavelength.

In order to improve auto-focus performance of self developed“cat′ s eye”detection system, three auto-focus performance influence factors are analyzed, which are speckle noise in active laser images, autofocus windows and field of view. According to the three factors, modified auto-focus algorithm and strategy are proposed. The experimental results show that the modified methods indeed improve auto-focus performance. Furthermore, it provides vivid and precise active laser images of thread targets in order for subsequent early warning of the detection system.

A circulate iterative blind deconvolution (CIBD) algorithm to restore turbulence-degraded images in the frequency domain is described, which focus on enhancement of accuracy and rapidity. The accuracy is enhanced by beginning with random frame and gradually increasing new frame to circulate iteration to get satisfactory restoration. Some measures are implemented to improve convergence rate, such as estimated point spread functions (PSF) by correlation matrix, adaptive steplength updating rule, condition of iterative termination and scaled projection gradient strategy. The experimental results of simulation show that the algorithm is efficient to reconstruct the degraded images from remote ground-based observations under different atmospheric turbulence intensities, and its performance is better than traditional multiframe blind deconvolutions (MBDs).

In order to early detect and locate circuit damage corona discharge, in accordance with its ultraviolet imaging features, the use of FPGA core processing platform is designed to ultraviolet and visible two-way signal acquisition, registration and fusion the real- time detection system. By optimizing the design of the hardware structure and fast image registration algorithm based on MicroBlaze soft- core control module, a method is proposed to achieve fast FPGA- based image registration, the realization of different focal lengths UV/visible real-time processing of video data fusion. The results show that this method can effectively improve processing speed and image fusion system efficiency, meets the UV signal detection and localization requirements. This method has been used in China Southern Power Grid line inspection.

Aiming at the characteristics of the ChangE′ 3 panoramic camera (binocular camera), an application of image quality evaluation method based on the structural similarity (SSIM) is proposed. After analyzing the ChangE′ 3 panoramic camera imaging principle and the traditional evaluation factors, the method is used for the quality evaluation of image pairs obtained by the panoramic camera. The evaluation factors can be applied to ChangE′ 3 evaluation of panoramic camera image pairs, and the method is superior to the common evaluation factors. Experiments show that this evaluation method as the quality evaluation factor is better than ever before, and it can apply in the assessment of stereo image matching subsequently.

A theoretical calculation model of scarfskin, the nozzle of the turbojet engine and exhaust plume for nonafterburning unmanned aerial vehicle (UAV) is built. The infrared radiation calculation formulas are educed under different observation orientation and elevation by the finite element analytical method. Both the distribution of temperature and pressure and the CO2, H2O concentration field are numerical simulated by the software Fluent, which assure that the numerical value is precise. The atmospheric transmissivity under different observation elevation angles is analyzed by LOWTRAN. The experimental results for a given UAV indicate that for the scarfskin radiation, 3.7～4.8 μm spectrum band can be ignored, so the 8～10 μm spectrum band is the main spectrum band. The distributing rule of radiation for the nozzle of the turbojet engine and exhaust plume for the 3.7～4.8 μm spectrum band is the same as that of 8～10 μm spectrum band. At the same time, the numerical value of the 3.7～4.8 μm spectrum band is larger than that of 8～10 μm spectrum band. The max radiations of scarfskin and exhaust plume are showed at the orientation angle of 90°and elevation angle of 45°.

A doping Nd:KGW femtosecond laser is used to ablate 0Cr18Ni9 stainless steel, and its ablation characteristics are studied. The surface profile of the ablated stainless steel and the associated effect in the ablation area are detected. Studies indicate that the ablation threshold of 0Cr18Ni9 stainless steel is 0.45 J/cm2; the ablation area successively appears grating structure, micro-convex structure, mastoid structure and concave structure, ablation hole along with the increase of the pulse number, and accompanied by heat affected zone,oxidation occurs at the ablation region; Microstructure in the ablation zone influences laser energy transfer and deposition further, local deep penetrating appears.

The paper adopts the fiber coupled diode laser welding system of LDF4000-40 and studies the welding performances of galvanized sheet with different thicknesses (t=0.7/1.4 mm) in the automobile industry. The results show that compared with the CO2 laser welding, it has better process stability, better welding bead with easier control, and faster welding speed. The tensile strength and elongation of the galvanized sheet welded joints meet the standard requirements of the motor industry and the cracks generate in the base metal parts. The galvanized steel weld metal includes ferrite and pearlite, so that the weld metal is 1.5 times the hardness of the base metal. Under the same condition of laser output power, the welding speed of fiber coupled diode laser increased more than 1.2 times compared with that of the CO2 laser.

The technology for high voltage level and three- pedestal width- adjustable fast pulse generation is revealed in this paper. The voltage level can be adjustable from 200 to 700 V, and the width of pedestal can be adjusted within 100 μs . This technology is already applied in the experiments and the experimental results match the expectations. Single longitudinal mode laser powered by this adjustable three- pedestal pulse can be smooth and stable. This technology can be used during the design of high power laser facility and other equipments with multi-pedestal high voltage fast pulse generator.

An optical parametric chirped pulse amplification (OPCPA) physical model is presented, and a splitstep Fourier technique is used to develop a three-dimensional OPA+CPA numerical code (3D OPA+CPA code), which can be used to model the broadband amplification, gaining narrowing, self-phase modulation, spatial selffocusing and the temporal signal-to-noise ratio (SNR) of OPCPA laser facility, and to optimize the design of OPCPA system. The SG-II-U-PW laser facility is studied numerically using this 3D OPCPA code, and the calculated results show that the ninth beam line is suitable to be modified for meeting the design goal of the SGII-U PW project. The 3D OPA + CPA code can be modified with ease to model and optimize the designs of femtosecond OPCPA system, and especially the future laser facility with exawatt (1018 W) peak intensity.

Laser direct manufacturing is a novel manufacturing technology. Fe-Cr-B-Si-C alloy powders are used in laser direct manufacture to make single track laser cladding layer and thin wall cylinder. The microstructure, phase structure and mechanical properties of single track cladding layer and thin wall cylinder are investigated by optical microscopy (OM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and nano-indentation techniques. The results show that laser direct forming metal parts are fully dense, and that there are no defects such as crack and pore. There is somewhat coarsening during interlayer microstructure, which can lead to weak mechanical properties. However, the whole properties of the thin wall cylinder may still satisfy the real part performance requirements. The change of laser scanning direction is beneficial to molten pool stirring, which leads to smashed dendrite structure in favor of microstructure homogenization.

The key to solar street lighting project design is the best combination of solar module, storage battery and lighting configuration. After the determination of lighting power, the battery capacity can be easily matched. Since light is impacted greatly by climate and geography, choosing a suitable power solar module is very important. Based on theoretical calculation or meteorological data design method, the calculated capacity of the solar module has large deviation. Based on conventional design methods, the solar module capacity is adjusted to 80 W from calculated 145 W. After continuous real- time tracking and monitoring, the results show that the design meets the design requirements, reduces system cost and saves the use of space.

Laser cladding is introduced as a process for preparing stainless steel -carbon steel metal laminated plates by cladding stainless steel powder on the carbon steel plate. The material properties, such as microstructure element diffusion, micro hardness and tensile fracture morphology, are analyzed through the metal material performance tests. The results show that laser cladding preparation of laminated plates can obtain dense and uniform layer; elements of Fe, Cr, Ni, et al. have a gradient diffusion around the combined surface and the diffusion region is about 12 μm , which indicates that combination of different materials by laser cladding belongs to metallurgical diffusion; micro hardness decreases from cladding layer to matrix, which makes a smooth stress transition between cladding layer and matrix, then enhance its overall mechanical properties; the yielded strength reaches 405 MPa and exceeds that of rolling laminated plates (326 MPa). Fracture morphology of matrix and diffusion zone belongs to ductile fracture and cladding layer is brittle fracture, further show that the interface of laser cladding laminated plates has a good combination performance.

The energy band structure, density of electronic state and absorption of S-doped wurtzite ZnO are investigated using first-principles based on density functional theory. These results indicate that the crystal lattice parameters increase with increasing doping ratio. Nevertheless, the electron mobility is enhanced as the band gap decreasing by S-doping. Optical properties further calculated show that, absorption spectrum shift to the red side after S-doping. Absorption spectrum peak increases with increasing of the S-doped amounts, so that the visible light and ultraviolet region of the light absorption are improved.

Dy3+ doped phosphors CaBi2Ta2O9 (CBTO) based bismuth layered-structure oxides is synthesized by high temperature solid- state reaction. The X- ray diffraction (XRD), scanning electron microscope (SEM) and photoluminesce (PL) properties of the phosphors are investigated, respectively. The study reveals that the strongest excitation peak of CBTO:Dy3+ locates at 450 nm, which covers the emission wavelength of the commercial blue LED chips, and that the emission peak at 574 nm corresponds to the electric dipole transition 4F9/2→6H13/2 of Dy3 + . The luminescent intensity of samples with different concentrations of Dy3+ ions is analyzed, and the optimum doped-Dy3+ mole fraction is 7%. According to Dexter′s theory, the mechanism of concentration quenching in CBTO:Dy3+ should be attributed to the mechanism of multipole-multipole interaction. The influence of charge compensators (Li+, Na+, K+) on the emission spectra of CBTO:Dy3+ is studied respectively, and the results display that luminescent intensity of the samples is improved.

Fourier transform is applied to write the lattice structure in self-defocusing LiNbO3：Fe crystal. In the process spacial second-harmonic generation is fabricated by array beam interacting with photonic lattice. The spacial second-harmonic generation has an influence on writing the lattice structure.Resulting in spacial frequency-doubling in photonic lattice, cleavage phenomenon of interference fringe in lattice, and Bragg bandgap broadening. The numerical simulations and theoretical calculations of one-dimensional photonic lattice prove that spacial secondharmonic generation is the major cause of affecting lattice structure. Experimental results show that spacial secondharmonic generationcan control the internal structure in photonic lattice.

It is liquid crystal on silicon (LCOS) micro- projector′s characteristic that an image is formed by the reflected light from the LCOS′ surface, and the illuminating beam angle of divergence needs to be small, the uniformity error of illuminating should be fairly well. According to these requirements, an illuminating system on LCOS is designed, the projection device consists of a parabolic reflector, fly′ s- eye lens, a polarizing beam splitter, condenser lens and so on. The parameters of the parabolic reflector and the fly′s-eye lens are analyzed in detail. It includes the beam angle of divergence, the total length for the light source and the intended square to be uniform illuminated. Based on the theory of fly′ s eye′ s inform illuminating and the relationship between parameters of the parabolic reflector and the beam angle of divergence. The design requirements are that the beam angle of divergence should be smaller than 10°, the total length of the light source should be 220 mm, the area to be illuminated is 20 mm × 20 mm. Finally collimating lens is designed to collimate the rays on the LCOS, the illuminance should be as large as 0.35 lx/m2. And it is demanded that the uniformity error on the surface of LCOS should be limited in 15% . Simulation results are acheived by Lighttools. Based on the line charts and the grid charts, it has satisfied the design requirements.

Compared with single- point scanning microscopy, multifocal multiphoton microscopy (MMM) can significantly improve the light energy utilization efficiency and imaging speed. Thus it has broad application prospects in life science. Unfortunately, there exists conflicts between the image quality and imaging speed in the available MMM systems. Although increasing focus number within a unit area can increase the imaging speed, too small focus distance will produce crosstalk between adjacent beamlets that will affect the longitudinal spatial resolution. High- density excitation focus array is simulated with Zemax, the distances between adjacent focus are reduced from 6 mm to 3 mm; the causes of noise in high- density multifocal multiphoton microscopic imaging system are analyzed; a square time- delaying plate based on the principle of time multiplexing technology is designed, which can generate different time delays between adjacent subpulses, therefore the crosstalk between adjacent beamlets is eliminated in high-density MMM imaging system.

To test a aspheric surface with F-Number of 4, a highly precise compensation system which is parallel light compensator system is designed. The design wavelength is 632.8 nm and the design residual is 0.0018 λ . A new method of solving the initial compensator structure which is composed of two lenses is discussed. Partial structure parameters are assumed in reason and the other parameters are calculated when the sum of Seidel coefficients from compensator and aspheric surface is the smallest. With the help of MATLAB, the Gauss image height of aspheric surface at the first surface of the compensator is compared with that of parallel light until the iterative error is less than preinstall. Thus the height of parallel light is fixed. Finally, retry to calculate the final initial compensator structure. Each surface′ s Seidel coefficient from iterative calculation is compared with that from ZEMAX, and the result verifies the reliability of this method.

Double electron beam interaction is studied by numerical simulation method. The simulation results show that when an electron beam (I) composed of many micro-pulses passes close to another electron beam (II) composed of many micro-pulses, the moving spatially periodic electric field of electron beam (II) can force the electrons in the electron beam (I) to follow a curve path, and electromagnetic radiation is stimulated by the acceleration of the electrons in the electron beam (I) along this curve path. In the same way, electromagnetic radiation is stimulated by the acceleration of the electrons in the electron beam (II) along this curve path. This novel electromagnetic radiation generated by double electron beam interaction effect is called double electron beam interaction radiation in this paper. Using a quasi optical resonator, coherent double electron beam interaction radiation with a high output peak power can be obtained.

In addition to the object reflective property at the laser wavelength, the echo intensity data acquired by terrestrial laser scanner is also related to other factors，which reduces the reliability and accuracy of object classification based on intensity data. The effects of instrument, distance, incidence angle, object reflector, and environmental conditions on intensity data are studied with Leica ScanStation2 laser scanner. The results indicate that with the increasing of distance, the intensity value increases at first and then decreases, and the maximum value occurs at about 15 m, while its standard deviation declines oscillatorily and tends to be stable after increasing to 55 m. The effect of incidence angle on intensity data is related to object properties, such as object reflectance at the laser wavelength and homogeneity. Colors close to laser wavelength and the color of laser itself generate higher intensity values, while introduce higher standard deviations. For the same object, the intensity value in dry condition is greater than that in wet condition. Environmental conditions have no significant impact on intensity value.

The self-developed portable angle scanning surface plasmon resonance biosensor is used in the quantitative detection of low concentration solution, because the existing quantitative detection methods are complicated and with low resolution. The validity of this method and the developed device is demonstrated by experiments. The quantitative detection is proceeded in glucose and glycine solutions. The detection results show that the direct detection of glucose solution distinguish the concentration of 0.1 mg/ml. The quantitative detection method of low concentration solution based on the surface plasmon resonance is simple. The developed device is portable and easy to operate. The rapid and real-time detection with high resolution can be realized by this method.

Raman spectrometer is widely used in the field of chemical research, polymer materials, biomedicine, drug testing, gem identification, etc. Miniaturization and on-site detection of the spectrometer are the two most important directions in the future. With its small volume and convenience to detect, portable Raman spectrometer supplies a non-destructive method for rapid detection in real-time detection field, such as drug testing, environmental testing, security, etc. The principle and constituent of Raman spectrometer are introduced briefly. The status and progress of domestic and international industrial portable Raman spectrometer at home and abroad are reviewed.

Amorphous alloy is a kind of promising metal material. Laser cladding amorphous composite coating can improve the properties of the material surface, and is an effective way to put amorphous alloy into the application. The latest progress and research status of laser cladding amorphous coatings are summarized in this paper, including material systems, microstructure and properties of the coatings. The main problems and the research direction of laser cladding amorphous coatings are also put forward in this paper.

The laser of 2 μm waveband has attracted considerable interests as mid-IR light source, due to their extensive applications in laser medicine, environmental monitoring, laser lidar, remote sensing and laser ranging. Tm,Ho:YAlO3 crystal with good mechanical and thermal properties has achieved multifold continuous and pulsed mode of 2 μm waveband lasers. The research and development on Tm,Ho:YAlO3 laser at 2 μm waveband are classified and summarized, which include the techniques of continuous-wave and pulsed mode for Tm/Ho doped YAlO3 and Tm, Ho:YALO3 laser output, and the latest development of high power Tm,Ho:YAlO3 laser. The main techniques include active Q-switch, passive Q-switch and Ho laser pumped by Tm laser. The prospect and applications of Tm,Ho:YAlO3 laser are discussed in the article.

An experiment system to measure the spontaneous Rayleigh- Brillouin scattering line profiles of gas is designed in this paper. A narrow bandwidth laser delivers a vertical polarization beam of continuous wave light at 532 nm. The beam is focused on the pressure controlled gas cell, interacts with gas molecules and generates the scattering signal. The spontaneous rayleigh- brillouin (RB) scattering line profiles of gas are measured at the lateral direction of 90° of the cell. The spontaneous RB scattering line profiles of N2 under the temperature of 300 K and the pressure of 300 kPa are measured by this system. The results of experiment and simulation results of Tenti S6 model are compared and the causes of the deviation between them are analyzed. It provides a reference for future space lidar measurement of air parameters.

A method is proposed to automatically analyze energy dispersive X- ray fluorescence (EDXRF) spectrum fast and accurately. Smoothing of spectrum, background subtraction and peak searching are used in the method. It not only can be applied to analyze single spectrum, but also can be used for analyzing a large number of spectra continuously. The method is evaluated by using the spectrum analyzed by micro- X- ray fluorescence in laboratory. Compared with Gaussian fitting, the result of the symmetric zero area method is basically the same but this method has the advantage of short computing time. It can obtain a good result in the case of the spectrum with big noise and well ability of picking out the weak peaks. On ordinary PC, the average time of analyzing a single file is less than 1 s while analyzing hundreds of files using this method. It can obviously reduce the work time and improve work efficiency.

The nephrite in the market come from different deposits, like Xinjiang, Qinghai, Russia and South Korea. The nephrite from the South Korea is a new kind of jade, which hasn′t been thoroughly studied yet. The chemical components, physical structures and geological character of different nephrite samples from Qinghai and South Korea are studied by Raman spectrum, Fourier transform infrared (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscope (SEM) and polarizing microscope. The testing results show that the chemical components are similar and the main geological composition of nephrite is tremolite, the feature Raman shifts are 667 and 1051 cm-1. XRF shows that the content of Fe has a positive correlation with the color. While the crystallinity of nephrite from Qinghai is better and the fibers are better aligned than the nephrite from South Korea. The differences in physical structures offer the theoretical basis for nephrite's quality evaluation.

The rules of soda lime glass that the refractive index and extinction coefficient varies with the frequency at different temperatures are studied. The dispersion curves of soda lime glass within temperature range of 90~520 K and frequency range of 0.1~1.5 THz by time-domain spectroscopy (TDS) system are measured. We can get the refractive indices and extinction coefficient corresponding to different frequencies by Cauchy equation, which are consistent with the experimental results. Then it can better fit the dispersion curve in a wide range by using temperature correction factor. So a method of solving the refractive indices and extinction coefficients of soda lime glass at different temperatures and different frequencies is got.

The surface strengthening agents OTR202 and OTR103 are used as active substrate of the surface enhanced Raman spectroscopy (SERS), and the rapid detection method of the carbaryl solution based on SERS is explored in this research. Firstly, the contrastive analysis of the normal Raman and SERS spectra of the carbaryl solution is proposed. Secondly, the effect of the surface strengthening agents and the addition amount of the measured samples on SERS spectra of the carbaryl solution is investigated. Lastly, SERS spectra of the carbaryl solution in the concentration range of 0.1~15.0 mg/L are analyzed. The linear regression is made between the intensity of characteristic peaks at 1374 cm-1 and the concentration of the carbaryl solution, the linear regression equation is y=414.5x + 481.59, and the determination coefficient R2 is 0.9864. The experimental results show that the detection limit for the carbaryl solution is 0.1 mg/L, and the detection method, which is applied in the surface strengthening agents OTR202 and OTR103 as active substrate, can be used to detect the carbaryl residue in water.

The under building Dreamline at Shanghai Synchrotron Radiation Facility (SSRF) is a wide range and high resolution soft X-ray beamline. There are many difficulties to overcome for building a beamline with such high target. Especially, the thermal deformation of optical elements is one of the main obstacles. Based on the focal parameters of SSRF, the thermal power density distribution absorbed by optical elements is calculated. Finite element analysis is utilized to perform the thermo-mechanical analysis of M1 and M2 to obtain the temperature gradient distribution, the surface displacements and the slope errors of these optical elements, and then ray tracing simulation is done. In addition, a thermal deformation correction device is designed to cancel the deleterious effects of these deformations. According to the result, even under the worst-case thermal deformation of the optical element surfaces, effective cooling and appropriate focusing corrections are able to cancel the deleterious effects of these deformation.