The expression for the Rayleigh range of partially coherent annular beams propagating through non-Kolmogorov turbulence is derived, and the influence of turbulence parameters (generalized exponent parameterα , inner scale l0 , outer scale L0 ) and the beam parameters on the Rayleigh range is studied. It is shown thatRayleigh range zR| turb in turbulence decreases with increasing intensity of turbulence, and is always smaller than Rayleigh range zR| free in free space; zR| turb decreases with increasing L0 (just for 3.6 < α < 4 ) and increases with increasing l0 ; zR| turb does not monotonically vary with the increase of α , namely, it decreases firstly and then increases due to increasing α . When α = 3.11 , zR| turb reaches its minima. Additionally, the influence of turbulence on the Rayleigh range increases with increasing coherence parameter β , beam width w0 and decreasing obscure ratio ε , beam orders M(N ).

Based on the extended Huygens-Fresnel principle, the propagation properties of electromagnetic Gaussian multi-Schell model beams through atmospheric turbulence in a slanted path are investigated in detail. Results indicate that the changing of transverse coherence length has an effect on the far-field intensity distribution and the beam width induced by atmospheric turbulence of the laser beam. Besides, the degree of polarization of the electromagnetic Gaussian multi-Schell model beams can change with the propagation distance, and it can reach a certain value when the laser beam propagates through atmospheric turbulence in a slant path. This result indicates potential applications for satellite-to-ground or ground-to-satellite laser communications.

Swept light source is a key component of fiber optic sensing demodulation. High-quality of the swept light source can improve the signal- to- noise ratio and demodulation precision of fiber sensing system. A Fourier domain mode locking (FDML) operating mode of the swept light source is reported. Semiconductor optical amplifier (SOA), fiber-optic tunable FP filter, isolator, fiber coupler and optical delay line form the swept source ring cavity. While a filter based on Febry- Perot (FP) cavity is designed to flat the output spectrum. The swept range is 1506~1566 nm, swept speed is 250 Hz, flatness is better than 0.3 dB, full width at half maximum (FWHM) is less than 0.16 nm, the average optical output power is 4.53 mW. The swept source has the advantages of simple structure, low cost and good flatness. As the light source of optical fiber sensor demodulation system, swept source has some practical value.

In order to meet the requirements of ground calibration of star sensor and assorted usage with single star simulators, a light source coupled by integrating sphere and multiple optical fibers is designed based on the characteristics of conventional light source of star simulators. The luminance of each single star emitted by star simulation is controlled by each coupled beam. According to the requirements of indicators, the types of light source, integrating sphere and optical fiber can be confirmed by analyzing the energy in perspective of photometry. Using simulation model established by Light tools and analyzing the simulation results, it is found that the fiber-coupled light source meets the design requirements, and the illumination simulation error of each magnitude is similar to the practical illumination error and both of them are not more than ±10%.

Based on signal spectral transforming principle, an all-optical return-to-zero (RZ) to non-return-tozero (NRZ) format conversion is realized by using a micro-ring resonator with the comb transmission spectrum and a narrow bandpass filter. Influences of devices′ parameters, such as different narrow bandpass filters, coupling conditions of micro-ring resonator and duty ratio of the RZ input signal, on eye-diagram quality of converted NRZ signal are investigated in detail. Results demonstrate that 2-order Butterworth filter is expected to decrease the influences of coupling conditions and the duty ratio of RZ signal on the conversion performances. In addition, by adjusting the ring-resonator size, the designed RZ-to-NRZ format converter is compatible with system having several bit rates signals. This will be better adapt to the development of future optical networks.<网络出版日期.2015-01-09

A stress element analysis method is proposed for calculating the stress field and birefringence at the center of fiber core with any shape of fiber stress region. With the help of solid mechanics module in COMSOL Multiphysics software, stress field distribution and birefringence at the center of optical fiber core with the different shapes such as rectangle, square, triangle, circular stress element are studied. The results show that the stress field and birefringence at stress-induced optical fiber core are independent of the shape and direction of stress elements if the area of stress elements is the same and the stress element is small enough. They are only related with the distance between the fiber core and the center of the stress element. When the stress element is close to the core, this relationship between birefringence and distance approaches inverse square. The correctness and effectiveness of stress element analysis method can be verified from the results. So with integration of the stress element, stress distribution and birefringence at fiber core with any shape of stress region can be obtained.

Variety discrimination for single rice seed is important to prevent the mixing and adulteration during seed production and to ensure the seed purity. A fast discrimination method for single rice seed by using the hyperspectral imaging technology is investigated. Hyperspectral images of rice seeds from ten varieties are collected over the wavelength region of 400~1000 nm, and the spectral, texture and morphological features of rice seeds are extracted. The discrimination accuracy of different features and their combinations is compared by using the partial least squares discriminant analysis, and the multiple progressive uninformative variable elimination algorithm combined with the partial least squares projection analysis algorithm is used for optimal waveband selection. The results show that the satisfactory discrimination accuracy, which is 99.22% and 96% for the training set and test set respectively, is achieved when mean, entropy and power features for the 23 optimal wavebands and morphological features are integrated. It suggests that multiple hyperspectral feature integration can effectively improve discrimination accuracy for single rice seed at the case of a small amount of wavebands, which basically meets the requirements of the national standards on the seed purity identification.

In order to improve the quality of blind image restoration, quantum bit code algorithm is proposed. Quantum clone is selected in immune system, and antibody controlled. Antibody is determined value in state of linear superposition at random, state of quantum is observed and obtained by binary. Blind image restoration model is built, quantum code convolution is filled void pixel. Finally, process is given. Simulation shows that blind image restoration reconstruction of this algorithm is clear and better, local manimum error (LME) is least, structural similarity (SSIM) is closed to 1.

In order to actualize image preprocessing of defect image on printed circuit board better, an improved self-adaptive image preprocessing method based on the total variation model is proposed. The image preprocessing model based on the total variation norm is analyzed, and its shortcomings are pointed out. The generalized total variation image preprocessing model based on L1 + p norms is discussed, the advantages and disadvantages are analyzed. An improved self-adaptive image preprocessing method based on the total variation model is proposed, the defect image noise of printed circuit board can be eliminated as far as possible by using the proposed method. At the same time, the edge faintness and ladder effect existed in the defect image can be overcomed better after denoising, and the image after denoising has more slippery and exquisite visual effects. The subjective and objective experimental comparisons among the four image preprocessing methods or models are achieved aiming at the defect image of actual printed circuit board, and the result indicates that the proposed method has good effect on defect image preprocessing of printed circuit board. What is more, the results are all detected better by adopting the proposed method for different printed circuit board defects.

Satellite-borne photoelectric imaging system can detect space objects effectively and detection distance is an important parameter to evaluate system performance. System detection distance model influenced by the number of imaging pixel is established, detector sensitivity, signal-to-noise ratio and imaging resolution respectively and derive detection distance equation based on sun radiation and deep space radiation character. And then relations between detection distance and exposure time, pixel size and optics effective aperture are simulated. The results show that the maximum detection distance is 12 km which is limited mainly by imaging resolution when object size is 2 m × 4 m , average reflectivity is 0.3, optics effective aperture is 100 mm, detector pixel size is 3.5 μm and focal length is 500 mm. The result can provide theory guidance for the design and system performance evaluation of the satellite-borne photoelectric imaging system.

Laser spot simulation is the important part of target characteristic simulation in hardware-in-the-loop (HITL) simulation system for laser guided weapon jamming. The HITL system composition and laser seeker theory are introduced. Laser spot simulation scheme based on correspondent ratio scaling in similarity theory is shown. Optical system model of laser seeker is established by LightTools, and the sizes of laser spot on detector′ s photosensitive surface in infield and outfield are calculated in different guided time. Laser spot simulation optimization methods based on HITL simulation system for laser guided weapon jamming are proposed. The research result indicates that under HITL condition the size of laser spot on detector′s photosensitive surface is bigger than that in outfield environment, and their changings are not the same. With the distance from the target decreasing, the size of laser spot on diffuse reflectance screen increases and this leads to the increase of laser spot on detector′s photosensitive surface. The result is helpful to improve the precision of laser spot simulation and the reliability of HITL simulation system for laser guided weapon jamming.

For measurements on particle size, an improved reverse Fourier laser measurement system (RFS) which based on disadvantage traditional Fourier system (FS) is presented. In the experimental parts, the results show that the increase in lower limit of particle size measurement by increasing the distance of scattering volume and lens can expand the range of particle size measurement. In addition, the different particle size measurement results and theoretical calculation results are compared. The experimental evidence and simulation results show that, this method is especially suitable for measuring small particles.

A novel method with high resolution has been proposed which is based on heterodyne interferometry and scanning probe to get the measurement values of superfinish surface scratch. But the optical nonlinear errors affect the measurement precision of the system. We adopt the Jones matrix to analyze the change of elliptic polarization caused by the composite error factors, which are polarization ellipticity and installation orientation error of laser source, phase retardation of quarter-wave plate and polarization leakage of polarization beam splitter. The measurement errors of frequency mixing about these elliptic polarization beams arriving at the photodiode detector are studied by vector theory. The results show that the measurement errors are periodic errors, and they are more affected by nonideal laser and polarization beam splitter. Also, the methods of reducing nonlinear error according to the numerical results in the system are suggested.

By selecting different types of thin plasma targets and applying two-dimensional particle-in-cell (PIC) simulation system, the acceleration behaviour of proton in the self-generated magnetic field induced by ultra intense laser and the thin plasma target interaction are studied. The results show that when the power density of interaction of intense laser is 1020 W/cm2, due to the self-generated magnetic field produced plasma target, the proton distribution exhibites space directional emission; the emission direction and the energy of the high energy proton are closely related to the plasma target surface. The higher proton energy, the smaller the divergence angle and the better proton accelerator effect are. In the round thin plasma target, the proton maximum energy reaches 41.1 MeV. This result has important application value for the inertial nano fusion fast ignition and tumour therapy.

An acousto-optic Q-switched Nd:YVO4 laser end-pumped by laser diode (LD) is used as the pump source, and a MgO-doped PPLN (PPMgLN) is chosen as nonlinear crystal. By optimizing the pump beam quality and mode matching, a mid-infrared pulsed optical parametric oscillator (OPO) is realized. In the experiment, if laser diode (LD) pump power is determined, mid-infrared laser output power is changed by the repetition frequency of the acousto-optic switch. When the repetition rate is small, the output power increases as the repetition rate increases. But when the repetition rate reaches a certain value, output power decreases as the repetition frequency increases. The optical parametric oscillator could be tuned from 2.95~4.16 mm by changing the period of PPMgLN.

Polyprogylene (PP) plastic is welded by using laser transmission welding technology. Feasibility of laser welding PP plastics is discussed. The orthogonal experiment is applied to study the influence of laser power, welding speed and mass fraction of carbon black on the welding strength and welding quality. Effect of line energy on welding strength is discussed. The results show that the laser power is the primary influence factor, followed by the welding speed, the last is the mass fraction of carbon black. The best welding parameters for PP are laser power of 50 W, welding speed of 15 mm/s and mass fraction of carbon black of 0.15%. Line energy has an impact influence on welding quality. When line energy is in the range of 1.5~3 J/mm, the higher welding quality can be attained.

In order to improve the flexibility of the control to far-field directivity, the double butterfly-shap silver nanostructure optical antenna is put forword. The influence of the far-field directivity caused by different structures and sizes is researched based on finite difference time domain method. The research demonstrates that, because of the exist of localized surface plasmon, far- field pattern shows a significant side lobe when the dipole is placed beneath the structure vertically. The increase of length is the key factory to make the side lobe appears in the farfiled pattern. The decrease of the gap between antenna arms can make the side lobe and the main lobe gain increase in the far-field pattern. The increase in antenna thickness causes a side lobe in the far-field pattern and the main lobe gain first increases then decreases. The results show that double butterfly-shap silver nano optical antenna can change the radiation directivity of the coupling dipole source.

Impurity-free vacancy diffusion (IFVD) induced quantum well intermixing (QWI) of red light diode laser wafer using silicon dioxide (SiO2) encapsulation is explored. The wafer has an active region of two 5 nm-thick GaInP quantum wells and three 8 nm-thick AlGaInP barriers. The 250 nm SiO2 dielectric layer is prepared through electron beam evaporation method. The QWI is induced by rapid thermal annealing for 60 s at different temperatures. Blue shifts and full width at half maximum (FWHM) are obtained through photoluminescence tests. A maximum blue shift of 29.5 nm is obtained at 900 °C annealing temperature and an optimal FWHM of 43 nm by the IFVD-induced QWI is noted at 750 ℃.

Increasing the imaging depth of frequency domain optical coherence tomography (FDOCT) is a key to expand its applications. The method of increasing the imaging depth of FDOCT which is based on the interpixel shift technique is investigated. The principle of the interpixel shift technique is discussed, and the relationship between theoretical maximum imaging depth of FDOCT and the pixel number of charge coupled device (CCD) is elucidated. Then the point spread function (PSF), imaging experiments of five-layer cover glass as well as the vivo imaging experiments of fingers are carried out to demonstrate the effect of interpixel shift technique on the enhancement of imaging depth. The imaging experiments of fingers show that the actual imaging depth increases to 1.98 and 1.12 times after using pixel shift technique in an OCT system with a 256-pixel CCD or a 512-pixel CCD, respectively. The Matlab software simulation validation method provides reference for the FDOCT system on the choice of the pixels of CCD.

According to Wolf and Richard′ s vectorial diffraction integral, a model is established, and the point spread function (PSF) in the two common conditions of confocal microscopy with a refractive index mismatch to study the effect of aberration induced by refractive index mismatch on imaging in confocal microscopy. The model is tested by experiment. When the beams focus into a spot through oil, coverslip and water, the full width at half maximum (FWHM) of the PSF along the z axis is broadened from 0.4391 μm to 0.931 μm with the detective depth from 0.5 μm to 10 μm . And the maximum intensity of the PSF is reduced from 1.161 to 0.4119. When the detective depth is 10 μm , the FWHM of the PSF with the refractive index match along the z axis is 1.059 μm , and its maximum intensity is 1. But the FWHM of the PSF with refractive index mismatch along the z axis is 7.5 μm , and its maximum intensity is 0.04632. When the detective depth is large, the aberration induced by refractive index mismatch can make light spot bigger, dispersive energy and influent the imaging quality.

The numerical analysis of the dynamics of a Gaussian beam in Bessel lattices which are induced by transvering the focusing photorefractive nonlinearity crystal is presented. The propagation properties of the Gaussian beam can be different with and without the lattices. In the absence of the lattice, the beam will present linear diffraction and nonlinear focusing in a homogeneous medium. The beam can overcome these effects in a homogeneous medium after transfering in a crystal with lattices. With different initial input conditions in the case of lattices, the input beam can overcome these effects and form a ring-shaped soliton or a circle-shaped soliton.

For low material utilization and low optical efficiency of the quantum dots thin film transistor liquid crystal display (TFT-LCD) backlight, a new model is proposed to form quantum dot micro structure in light guide plate. The new structure make the blue light emitting diode (LED) pump into high color rendering index (CRI) white light. The backlight system is built, and the study on ray tracing simulation and parameter optimization shows that the new quantum dots backlight has the advantages of high optical efficiency and low cost. The experimental and theoretical results match well with each other.

The finite difference time domain method (FDTD) is used to investigate the phenomenon of Fano resonance and near field distribution in the quadrumer clusters comprising nanorings or split nanorings with two gaps. The calculation results show that one prominent Fano resonance is observed in the extinction spectra of quadrumer cluster composed of nanorings and double Fano resonances are obversed in the quadrumer cluster comprising of split-nanorings. The new Fano resonance appearing in the spectra is caused by the split nanorings in quadrumer cluster forming the dark quadrupole mode. The spectral position and modulation depth of Fano resonance can be largely tuned by adjusting the angle and separation of the nanorings. These results can be used as guideline in multiwavelength surface-enhanced Raman scattering and biosensing.

To meet the requirements of satellite laser switching network, such as fine robustness and high physical realizability, emulated-optical burst switching (OBS) is selected as the architecture of relay satellite, and an on-board resource reservation protocol, whose offset time is constant, is proposed combining the ground resource reservation methods. Traffic prediction is used to differentiate the data burst into single burst or burst stream according to the destination and quality of service (QoS), then resource reservation is accomplished successfully. To validate it, mathematic models of mean end-end delay, throughput, link utility and burst loss probability are established. The results of analysis and emulation show that the protocol can reduce the reconfiguration time and switching time of optical switch matrix through burst stream scheme, and decrease the complexity and cache size requirement through the E-OBS architecture, so the new resource reservation protocol meets the requirements of satellite laser communication.

In order to study beam waist width and waist location of cosh-Gaussian beams in a Gradient-index medium, the propagation field of cosh-Gaussian beams in a gradient-index medium is deduced, and expressions of spot size , beam waist width and waist location by using the definitions of second-order moment are presented. Based on the expressions, the influence of the Gradient-index medium on the spot size, beam waist width and waist location are mainly discussed. The results show that spot size cyclical changes in a Gradient-index medium with increasing distance from the propagation, and the cycle is determined by gradientindex parameters. With increasing eccentric parameters, beam waist width first decreases then increases and stabilizes at last, and the spot size oscillation amplitude is determined by eccentric parameters.

The geometrical quantum discord (GQD) between two atoms in the system of two two- level atoms interacting with few- photon superposition states cavity is studied. The evolution of GQD under different coupling strengthes between atoms is given by the numerical method. The influences of coupling constant between atoms on GQD are discussed. The results show that the evolution regularity of GQD between atoms displays from irregular oscillation to periodicity evolution with the increase of the coupling constant. On the other hand, the peak and average of GQD sometimes increase and sometimes decrease. It shows that there is a nonlinear relationship between GQD and the coupling constant.

According to the requirements of high-resolution spaceborne camera focusing mechanism, a dual readings multi-turn absolute encoder is designed. Accuracy and high-resolution glass plate is the first level absolute matrix optical code disc; metal plate with light weight and small size is the second level absolute matrix optical code disc which completes the count of the number of first level disc turns; double slit and double reading system to meet the circuit cold backup. The encoder can offer that resolution of 80″, accuracy between ± 100″, cylinder number is 16, its dimensions for φ 50 mm×50 mm, weight of 270 g. According to the requirements of identified spaceborne product, the function of encoder is verified through kinds of experiments. The experimental result shows that the encoder is stable, reliable and satisfies for the requirement of highresolution spaceborne focusing mechanism.

Directly pumping rare-earth ions or transition metal ions doped laser materials can greatly reduce the complexity of laser system and improve the efficiency. Searching a suitable substrate material and ion energy level structure is key factor to realize the mid- infrared laser directly pumped by laser- diode (LD). Recently research progresses in mid- infrared solid- state laser of laboratory are introduced. This paper includes experimental research on the high power, high efficiency, LD direct pumping transition- metal ions doped II- VI materials laser and rare-earth ions doped crystals, glasses, fibers, and ceramics laser. Those lasers are featuring simple structure and low cost and covering 2~5 μm range wavelength. Cr2+-doped ZnSe and ZnS, featuring large absorption and emission cross-section, high quantum efficiency at room temperature and very low excited state absorption, are the most popular candiadate. Er3 +/Tm3 +/Ho3 +-doped glasses possess rich energy level to emission multi-wavelength. By controlling the structure of rare-earth ions lattice field in different materials, it can realize tunable mid-infrared laser output.

The alkali vapon laser shows great potential because of its high quantum efficiency and outstanding heat dissipation ability. The basic principle and research development of alkali laser are introduced. The obstacles in research are analyzed, the solutions are summarized, and their deficiencies are pointed out. The future development of alkali vapor laser is discussed.

Due to the limitations of packaging, waveguide structure and other factors inducing the asymmetrical beam quality on fast and slow axis, diode laser is usually used as pump source and power convertor, it is difficult for diode laser to be used as a high- brightness laser source directly. The development of an incoherent beam combining technology-external cavity feedback grating spectral beam combining, which could improve the output optical power density and output beam quality of semiconductor laser, is introduced. A number of important trends in the development of semiconductor laser spectral beam combining technology are summatised, which provides a reference for future development of semiconductor laser spectral beam combining technology.

The basic concepts and theories of super-resolution restoration method is introduced. Some applications focused on common method of super-resolution restoration is summarized. Their theoretical basis, advantages and disadvantages, and scope of applications are exhaustively analyzed. The applications of super-resolution restoration theory is introduced. Overall, the super-resolution restoration methods are divided into frequency domain method and space domain method. Frequency domain recovery method is simple in principle and easy in calculation. But its motion model is shift model have no generality. Meanwhile it is difficult to use the priori information of the image to help super-resolution restoration. Space domain recovery method can be easily taken degradation and motion blur. More perfect priori knowledge is added. Compared with the frequency domain method, space domain superresolution restoration model is more close to actual degradation processes and currently the most widely used superresolution restoration method.

Compared with silica glass,chalcogenide glasses possess high refractive indices (2.0~3.5), low photon energies (lower than 350 cm-1), wide infrared transmission window, larger nonliner refractive indices and particular photoinduced properties. Chalcognide glass based micro-nano photonic devices have attracted so much attention. The research progress of chalcognide glass based micro-nano photonic devices are reviewed in terms of fabrication, property and application of devices. The current situation of the study from several research institutions is summarized and stated. Their further development prospect is also discussed.

Photo-acoustic spectroscopy can be used to detect trace concentration gas. The total size can be made small, making it possible to realize portable in situ measurement. The critical technology of photo-acoustic detection is the miniaturization of absorption cell and microphone, which determines the sensitivity and volume of the system. Recent progress of photo-acoustic spectroscopy detection technology in miniaturization and integration is summarized. Three kinds of light sources, absorption cells and photo-acoustic resonators are analyzed and compared, respectively. Meanwhile, the latest progress of Beijing Institute of Aerospace Control Devices is also provided. The quartz tuning fork enhanced photo-acoustic spectroscopy technique is taken to realize miniaturization of absorption cell and photo-acoustic resonator. A compact packaged quartz tuning fork coupling with fiber is demonstrated. A Tm/Ho doped fiber amplifier is used to realize the 2 mm wavelength output with the power of 200 mW, and ammonia and carbon dioxide can be measured simultaneously.

Optical frequency-locked multicarrier is a light source which has a fixed frequency spacing between subcarriers. Some methods commonly used to generate optical frequency-locked multicarrier source in recent years are introduced. The differences between these methods are compared while the advantages and disadvantages of each method are analyzed. The comparison will provide reference for the related research in the future.