In order to realize the figure accuracy of λ/100 peak-vally (PV) value for the lithographic projection objective, the effect of gravity deformation on the optical performance of large-aperture Fizeau interferometer with super accuracy has been deeply analyzed. The optical configuration designed with a wavefront aberration of λ/1000(PV) and a numerical aperture(NA) of 0.36 in image space are employed to test the spherical surface with a diameter larger than 300 mm. One element in the configuration is analyzed by the finite element method (FEM) under two supporting types: adhesive support and retainer support. Based on the finite element analysis(FEA) results, surface deformation and body displacement due to gravity are obtained under a certain condition of load. By Zernike polynomials, the surface deformation is fitted, the wavefront error is acquired, the optomechanical conversion is finished, and a proper supporting type is proposed. When this supporting type is applied to the whole configuration, the wavefront aberration of the system achieved is better than λ/100 (PV). The result verifies that super accuracy can be reached. Besides, the data offered here will be useful for a reasonable interferometer design.

A numerical radiative transfer model based on matrix-operator theory to simulate the underwater inelastic scattering is presented. The assumption that various radiant energies decrease approximately exponentially with depth in a homogeneous layer is introduced to incorporate the inelastic scattering process as a source operator to the model. Validation by the Mobley standard problem 7 of underwater radiative transfer and comparison with the results of Hydrolight 5.0 show that the processing of the multi-scattering and inelastic scattering in this model is correct. So we conclude that this model is a suitable tool for simulating all radiative transfer processes under water. Simultaneously, with three-component model, this underwater radiative transfer model is used to simulate the effect of each components of natural water on inelastic scattering and inelastic fraction in the remote-sensing reflectance. The investigation reveals that only in clear water bodies, the inelastic fraction resulted by the water Raman scattering is high. With the increasing concentration of gelbstoff and chlorophyll, the inelastic fraction increases in the relevant wavelength, but either gelbstoff or chlorophyll restrains the inelastic scattering process of each other. And suspended sediments reduce the effect of inelastic scattering significantly which is even neglected in some water with high concentration of suspended sediment.

Ground-based monitoring of the distributions and dynamic change in local area of trace gases can play an important role in pridicting the local atmosphere and designing the space-based instruments for sounding atmospheric moleculars. Based on the trace gas inversion algorithm SFIT2, the optimization process is improved and a novel inversion model is developed based on truth region method. A solution to the convergence of algorithm when the a prior i and true atmospheric information have great differences is found, and effective inversion of trace gases is realized when atmospheric parameters are hard to get. The total column amount and the volume mixing ratio of carbon monoxide are retrieved from the ground-based infrared ultraspectral data during September and October in Beijing. The results improve the validity of this modified algorithm and the ability for understanding the trace gases and their effects on environment and climate.

A seawater salinity measurement system based on prism model multi-refraction is presented in order to improve the salinity measurement precision using optics refraction. The beam angle of refraction is expanded by using prism model other than parallel model, and is enlarged by setting multiple-prism-units further. So the measurement precision is improved greatly. The measurement system is developed after design and simulation. After laboratory experiments and sea experiments with ALEC sensor, it is indicated that the developed system is effective with a measurement resolution of 0.0012‰, repeatability error less than ±0.016‰, and measurement error less than ±0.1‰ compared with ALEC sensor.

Because the strong absorption characteristics of chromophoric dissolved organic matter (CDOM) and particulates at the short wavelength have strong impact on the biology community in the sea ice and underlying seawater, the absorption characteristics of CDOM and particulates in Liaodong Bay are studied. Absorption of CDOM in sea ice is 1/5~1/2 of that of the underlying seawater. The results show that the maximum absorption of CDOM in the sea ice often appears at the surface layer and the bottom layer. The maximum absorption of particulates in the ice sea often appears at the surface layer because of the atmospheric fallout. The slope range of CDOM is 0.0122~0.0231 nm-1 in sea ice, and 0.0174~0.0190 nm-1 underlying seawater of Liaodong Bay. The slope profile distribution of CDOM of sea ice is greatly influenced by the sea ice growth rate and CDOM underlying seawater. The more concentration of CDOM and particulates in sea ice, the more shifting of attenuation coefficient valley value to the longer wavelengths will be.

Scattering and polarization properties of particles, such as O2, N2, CO2, water droplets and aerosol, were analyzed by the Mie scattering theory. The theoretical skylight polarization patterns were simulated with different particles and analyzed by making comparisons with real-time measured results. Systematic theoretical studies on the particle′s scattering and their influence on celestial polarization patterns were performed. The absorption and scattering coefficients of different particles were diagnosed with different sizes and complex refractive indices, also were the polarization degree and intensity with different scattering angles. Through the comparisons between measured results and theoretical models determined by gaseous and non-gaseous particles, the conclusion was got that the celestial skylight polarization patterns were mainly decided by gaseous particles while the appearance of neutral point near horizon and the attenuation of polarization degree at low sun elevation were induced by non-gaseous ones.

An algorithm of demodulating dynamic phase difference based on Hilbert transform is proposed according to the principle and signal expression of fiber interference turbulence measurement system. The results of numerical simulation show that waveform phase difference and turbulence′s random phase difference can be demodulated by this method and absolute error is less than 10-3, which is in accordance with the results of correlation method. Compared to the correlated algorithm, the algorithm of Hilbert transform doesn′t have smooth effect on signal and doesn′t need to set correlation length, so it can reflect characteristic of signal frequency better. This research provides a new method for measuring turbulence random phase difference.

The parameter errors of the flat-field holographic concave grating including radius error, recording geometry error and use geometry error are induced by the fabrication and usage. In order to give theoretical guidance to the design and assembly of the spectrometers, the geometric ray-tracing method is used to analyze the image widths and the meridian focal lines for different parameter errors. It is discovered that, for a great parameter error range, there are parallel displacement and tilt which affect the parameter errors. The numerical calculation results indicate that, in a large neighborhood around the design point, the parameter errors can be compensated by each other and the spectral resolution can be as good as designed after compensation of the errors.

In order to get precise testing results from the instrument used for measuring the diffraction efficiency of plane grating, the analysis has been done on the instrument. Through analyzing the main factors that spectral broadening of exit beam and cross-section change of diffracted beam, which influence the testing results during measurement, the relation between wavelength and groove density of them is given. Based on a large number of experimental data, multiple linear regression analysis is used to establish regression equation based on two primary factors which influence the testing result during the testing process, and the equation is proved to be exact and credible not only in theory but also in experiment. Furthermore, the equation has been programmed in the testing programming, and it can correct the testing results automatically after finishing the test. By the results, the testing results which have been corrected are closer to the theoretical value, and the difference is less than ±2%, which prove that the method can be used to measure the diffraction efficiency of the plane grating. This method is strongly real-time, and any change is not necessary to the components of the instrument, which can satisfy the requirements of simple operation, testing speediness and preciseness.

A new type single-mode single-polarization photonic crystal fiber based on index-matching coupling has been put forward and its principle has been elaborated. A full vector finite element method is employed to simulate the fiber properties. When polarization dependant loss is larger than 4.08 dB/m in the wavelength from 1.26 to 1.7 μm and as diameters of air hole 1 and 2 between central and edge cores are 2.4 μm, the bandwidth of single-mode single polarization can reach 440 nm. The x-polarized mode exhibits a high leakage loss of 26.93 dB/m and the y-polarized mode exhibits a low leakage loss of 0.01 dB/m at a wavelength of 1.31 μm; the x-polarized mode exhibits a high leakage loss of 38.66 dB/m and the y-polarized mode exhibits a low leakage loss of 0.05 dB/m at a wavelength of 1.55 μm as diameters of air hole 1 and 2 are 2.6 μm. This photonic crystal fiber has a high bandwidth and polarization dependant loss in the 1.31 μm and 1.55 μm communication window.

Based on analyzing the restriction of space-time coding used in the free space optical communication, the intensity superposition code is propounded to increase the channel capacity of the optical multiple-input multiple-output (MIMO) system. The code/decode rules for the system are designed. The channel capacities of different system forms are analyzed. The decision thresholds are chosen, and the bit error rates (BERs) of different system forms are computed. The simulation result indicates that the channel capacity of this system is more than doubled channel capacity of the traditional system. And the BER falls very fast when the signal-to-noise ratio (SNR) is more than 10 dB.

The analysis of the phase noise effect in the optical frequency domain reflectometry (OFDR) is presented. A model of distribution function of phase noise is built. Simulations and further experiments demonstrate the effect of phase noise on the measurement of reflection signal and Rayleigh backscattering signal due to the finite laser linewidth and the influence of phase noise under different reflectivities. The results show the phase noise is the main issue which limits the resolution and measurement range. Under condition of the measurement range reaching the coherent length or strong reflection in fiber links, the much more significant phase noise will affect reflection signal of a longer range. According to the analysis, we should pay much more attention to the phase noise of laser while designing OFDR systems.

The characterics of the all-optical orthogonal frequency division multiplexing (OFDM) generation based on a dual-arm Mach-Zehnder molulator (MZM) is investigated. It was found that the all optical OFDM subcarriers generation greatly depend on radio frequency (RF) and DC bias voltage of the dual-arm MZM. The system degradation induced by carrier fluctuation on the OFDM transmission performance was studied. A new parameter, namely carrier equalization was defined, and it can accurately describe the quality of the all-optical OFDM carrier generation. Different best working points have been selected to generate 2,3,4 and 5 orthogonal optical sidebands by adjust the parameters. At the receiver end, OFDM demodulation based on optical discrete Fourier transform was realized by using the Mach-Zehnder time delay interferometer and the optical gate. The bit error performance versus the phase of optical gate and bandwidth of optical filter was measured and at last, the performance of a 5×20 Gb/s transmission system based on all optical OFDM was studied.

The basic principle and realizing method of polarization diversity receivers to eliminate polarization-induced fading in fiber optic interferometers are studied. Theoretical analysis shows that bi-state polarization diversity receiver can reduce polarization-induced fading. The optical fiber sensing system is built to test the bi-state polarization diversity receiver technique, with the minimum visibility of 0 at single way and 0.4 at bi-state polarization diversity receiver. The result shows that phase carrier demodulation technology adopted by the system can realize stable detection of the signal.

Fiber-optic image bundles are used by the wide view field, hyperspectal imager to fold view field in order to improve its performance. As a special optical element, the fiber-optic image bundles not only have the function of image transmission, but also have discrete sampling characteristics. Therefore, these require a new method to evaluate the image quality of fiber bundles. According to the definition of contrast, the contrast transfer function of fiber-optic image bundles is deduced. Accordingly, the characteristics of contrast transfer function of fiber-optic image bundles are studied. The simulation results show that the contrast transfer function shows a convergence characteristic at the domain very close to the Nyquist frequency and Nyquist frequency division. The convergence rate associates with the frequency deviation and the number of fibers in bundles. The contrast transfer function shows a clear convergence trend with the increase of fiber number, and converges to the average value at other frequency domain when fiber number is less than 100. In addition, contrast transfer function cycles oscillation with the change of initial position.

It is found that two reflected walls of fiber micro-cavity fabricated by one-step femtosecond laser micro-machining technology are not perpendicular to the fiber axis. The cavity shape is decided by the relative position of focused femtosecond laser and fiber, which can be approximated as V-shaped when femtosecond laser is focused on the side surface of the fiber. Compared with conventional fiber Fabry-Pérot (F-P) cavity, the free spectral range, optical loss and the interference fringe of the V-shaped fiber F-P cavity contrast change with the wavelength, showing abnormal characteristics. By introducing the concept of inclination factor, V-shaped fiber micro-cavity model is constructed, the cavity interference formula and the V-shaped micro-cavity interference theory are established. According to this theory, the effect of reflector inclination degree on interferogram characteristics of V-shaped F-P micro-cavity is simulated. The simulated interferogram is verified by experimental results.

Modulation transfer function (MTF) is one of the important parameters of high-spatial-resolution satellite optical cameras. A new method for in-flight MTF measurement using periodic targets is presented. It can directly obtain the MTF value at Nyquist frequency and MTF plots by parametric model. The experimental results show that the satellite optical camera′s MTF can be directly and accurately acquired by deployment of five groups of non-integer pixel (ground sample distance) interval of three-bar targets in cross and along track directions respectively, and can be arranged with the large-area target in homogenous dark background. The error is less than 5% and the approach can satisfy the application requirements for spaceborne estimation.

A digital micromirror device (DMD) is introduced to the ghost imaging via compressive sampling (CS). In this scheme, the image of object can be obtained using the bucket detector which has no spatial resolution. If the imaging scheme is applied to the multi-spectral imaging, multi-spectral images of object can be obtained using a linear array detector, which reduces the complexity of detector in imaging. The principle of ghost imaging is clarified with the correlated imaging the theory of CS. According to the imaging principle, the experimental demonstration device is assembled, and the object′s image is achieved accurately in the experiment. Ghost imaging and ghost imaging CS are compared to show that the latter has a better performance. Meanwhile, according to the experimental results, the resolution of the imaging system is decided by the size of unit on the DMD when the aperture of lens is big enough. Based on this imaging system, the multi-spectral imaging is carried out. The intensities at different wavelengths are recorded by the linear array detector, and the multi-spectral images of object are achieved in the experiment.

A novel fringe projection profilometry based on one snapshot color sinusoidal fringe pattern is proposed. One color fringe pattern encoded with a sinusoidal fringe and two uniform intensity patterns is projected by a digital video projector and the deformed fringe pattern is recorded by a color charge coupled device (CCD) camera. The captured color fringe pattern is separated into its red, green, blue (RGB) components and division operation is applied to red and blue channels to reduce the effect of non-uniform reflectivity. Shape information of the tested object is decoded by applying an arcsine algorithm to the normalized fringe pattern. A simple technique is introduced to compensate for nonlinear intensity response of the digital video projector. The experimental results and the comparison with four-step phase-shifting method demonstrate the validity of the proposed method.

To guarantee the palmprint image definition satisfying user′s requirements acquired by non-contact palmprint recognition system and shorten recognition testing time, the relation model between palmprint image definition and error recognition rate is established, and the improved non-contact on-line palmprint recognition simulation system is realized. The image definition evaluation function is introduced, and the relation model between image definition and shooting distance is established. The relation model between image definition and error recognition rate is established. The non-contact on-line palmprint recognition simulation system is realized which is based on image definition evaluation module. The experimental results show that the improved simulation system ensures the effectiveness of the image acquisition and reduces the error recognition rate.

An image displacement measurement technology based on double phase-encoding joint transform correlator (DPEJTC) is proposed. Firstly, a phase mask is generated electronically and applied to encode the reference image. The encoded reference image is overlaid with the target image to form the input image. Joint power spectrum (JPS) of the input image is obtained by a Fourier transform. Secondly, a filter is applied to JPS which is encoded by the same phase mask. After an inverse Fourier transform, a brightest peak in relation to the displacement between the reference and target image appears in the correlation plane. Displacement measurement of multiple images with this method is given. In comparison with the methods based on traditional joint transform correlator (JTC), this method can use the space of the input plane efficiently, disperse the auto-correlation item into system noises and remain the cross-correlation item only, which is convenient for detection. Comparing with different displacement measurement technologies, results show that our method takes edge over the other algorithms, and its root mean square errors (RMSE) can remain within 0.1 pixel.

An optical system working in 120~180 nm is developed for the study of ionospheric imaging spectrometer carried by satellite in China. The scheme, that the telescope is an off-axis parabolic mirror and the imaging spectral system is a single toroidal grating, is assumed with comparing different programs in foreign countries, based on characteristics of targets. Then the theory is studied by introducing the surface equation of the grating and optical path function, to get a novel broadband aberration-corrected method to resolve the disadvantages of traditional single grating structure, non-homogeneous aberration correction and low spatial resolution. The original structure is obtained by Matlab and is simulated by Zemax. A system operating in 120~180 nm with F-number of 6.8, focal length of 102.3 mm is designed. This imaging spectrometer has high spatial resolution and spectral resolution. The results demonstrate that aberrations are totally corrected, the modulation transfer function (MTF) of all field of view is more than 0.7 in the waveband, and the spectral resolution is 0.56 nm. It proves that the design which can satisfy the requirement of the design specifications is more convenient and more predominant.

To measure the sub-pixel image motion which is caused by satellite attitude instability or vibration, the optical joint transform correlator (JTC) is used, which is based on using the auxiliary plane CCD to record the image motion in the focal plane of the satellite camera. The principle of this method is described, and the experimental platform is built. The measurement performance of the JTC is researched. The results show that the JTC can measure the sub-pixel image motion of the space camera entirely, and the accuracy is not variable with the contents of the input images. The measurement error submits the normal distribution with the mean of zero, and the root mean square (RMS) error is no more than 0.12 pixel under the conspicuous level of 0.05. This can meet the operating requirement of the space camera completely.

Three-dimensional vision measuring technique aims at automatically reconstructing the properties of object and scene such as shape, motion, and deformation from one or more images or video clips in the real world around us, so that three-dimensional true environment can be recognized and understood. To solve the problems such as brightness change, scale change, rotation change and noise in conventional approaches, a new three-dimensional vision measuring technique is proposed. Firstly, the multi-modal isotropic monogenic features which include geometric feature (local orientation), structure feature (local amplitude and local phase), color phase and color texture are extracted by Poisson kernel and Riesz transforms. Secondly, a novel multi-modal feature descriptor and a similarity measurement function are constructed by simulating human vision function. Finally, the proposed similarity measurement function is applied to stereo matching and three-dimensional vision reconstruction. At the same time, the qualitative and quantitative evaluations are finished on the synthetic and natural stereo images.

A semi-empirical theoretical method for water droplet size fast calculation is presented to resolve the problem confronted with the measurement of wet steam scattering light distribution in steam turbine. Phase function for different droplet size is numerically calculated based on the Mie scattering theory, and by Gaussian fitting of the phase function curves in the forward small angles, we get an analytic approximation resolution for Mie scattering function. At last, a semi-empirical function for light scattering ratio with the droplet parameters is obtained by further curve fitting. Light scattering experiment for water droplets size measurement is carried out in a simulated steam turbine under various work conditions. Scattering light intensity distribution is received using a CCD camera, and the droplet radium is real-time inversed by means of the semi-empirical function. Because of the restriction of the range of the droplet size distribution and the approximation of the theory, the improved model can well resolve the problem of wet steam droplet parameters online inversion.

With a semiconductor saturable absorber mirror (SESAM), a simple folded cavity has been designed to achieve mode-locking with a single output. The plane mirror is employed as a cavity mirror as well as an output coupler. The grin lens is employed as the optical coupler to shape the single diode laser, the stable continuous wave mode locking is achieved with the pulse width of 5.2 ps and the repetition rate of 100 MHz. The average output power is 800 mW with the pump power of 3 W, and the optical-optical conversion efficiency is 27%. The characteristics of the laser cavity are analyzed by computer.

Aluminum alloy 2A02 is shocked by using the NdYAG laser with 1064 nm output wavelength and 20 ns pulse width. The surface hardness and residual stress of sample are measured, and the sub-structure of grain and its evolution behavior induced by laser shock are analyzed via the inverse fast Fourier transform (IFFT) method. The experimental results indicate that the surface hardness of the laser-shocked material increases by 50%, and the residual compressive stress of the laser-shocked test material reaches above 120 MPa. The transmission electron microscopy (TEM) and IFFT analysis of microstructure demonstrate that there are different types of dislocation configurations in the laser shocked area, mainly including edge dislocations and central dislocation bands; and the dislocation walls refine the original grain. The dislocation dipole close-array becomes the characteristic element of the nanocrystalline under the non-equilibrium deformation condition endowed by laser shock. Therefore, the complex dislocation configurations and the crystal lattice distortion induced by laser shocking are important to the improvement of surface hardness and residual stress.

Based on the fast data processing ability of field programmable gate array (FPGA), a novel digital servo control system overcoming the paradox between the locking precision and the control range with double proportional integral derivative (PID) algorithm is introduced. The digital servo system improves the persistent time of phase locking greatly. Using sinusoidal and integrating scan for the length of optical cavity respectively, the auto-search function is realized when the system is out of locking. The search time is shorter with the former method than the latter; while the latter method is more stable and has longer persistent time. Compared with analog servo system, the locking precision of digital circuit is slightly lower, which is limited by the electronic noise and processing speed of FPGA. However, the digital servo system has obvious advantage in locking persistent time.

The error signal used for stabilizing a laser frequency to an external bowtie-shaped ring cavity is analyzed theoretically based on the Hnsch-Couillaud frequency locking technique. In the experiment, the frequency of a 1583 nm fiber laser is locked to the longitude mode of a bowtie-shaped ring cavity with a KTP crystal inside it. The setup of this locking scheme is simple, and the technique is rather easy to operate, so it can be widely used in the laser technology, trace gas detection or other areas.

A single-image-based three-dimensional (3D) reconstruction method of an axisymmetric forge piece is proposed. The imaged circular points are solved from two paralell cross sections extracted from the image. Combining with the epipolar constraint, the 3-parameter constraint equations of the imaged absolute conic are established and the intrinsic parameters are solved. The imaged meridian and latitude of the surface of the axisymmetric forge piece are extracted based on the planner projection characteristics between two paralell cross sections. Then 3D shape of the axisymmetric forge piece is reconstructed based on the corrected imaged meridian. The visible region of the cross section is computed based on Laguerre formula, and an equal-arc sampling strategy is proposed based on the extracted imaged meridian, solving the inconsistent resolution problem of conventional texture extraction algorithm. Experimental results indicate that the large axisymmetric forge piece can be reconstructed with its own geometrical constraint from sinlge image without any auxiliary calibration equipment and the reconstructed shape and effective texture can be obtained.

Aiming at solving the problems such as low efficiency, high labor intensity and unsatisfying detection accuracy in traditional automatic brick stacking, a machine vision based automatic brick anomaly detection and recognition method is proposed. Brick images are captured from the brick delivering machine and the pit car are de-noised by applying an improved cross-like median filtering. Edges of bricks are extracted using the Canny edge detector. Vertical edges are detected by constraining polar angles in the Hough transform for analyzing the shape of the bricks. Anomaly detection is performed by measuring the length and width of the bricks in each column. Experimental results indicate that the average detection accuracy is 98.2% for brick-missing, brick-shifting and brick-tilting in one-scale brick stacks and multi-scale brick stacks. This meets the requirement of auto detection and recognition of brick anomaly in the automatic brick stack system of firing common bricks.

A magnetic resonance imaging (MRI) guided approach is introduced aimed at improving the spatial resolution and image localization errors of diffuse optical tomography (DOT). This approach allows incorporation of the priori MRI-based anatomical information through a segmented finite element mesh of a human brain. Since there are few existing literatures discussing the classification choice of the brain model and the settings of optical parameters, we propose three imaging quality evaluation indices in 3D space using point-spread-function (PSF) simulation, and provide a thorough evaluation of the image quality under condition of different tissue the classification and optical parameters. Meanwhile, reconstructed images are given in 3D space with depth information. It is indicated that a four-layer brain model: scalp, skull, brain and cerebrospinal fluid, produces the best image quality and the image quality is relatively even over the entire field of view. The effect of optical parameters′ variation within a certain range is relatively small and negligible.

A method using chirp-matching optical parametric chirped pulse amplification (OPCPA) scheme to improve the signal-to-noise ratio (SNR) of ultrashort laser pulse is proposed. Comparing the chirp-matching OPCPA scheme with the usual OPCPA scheme, it is shown that the chirp-matching OPCPA scheme can improve significantly the SNR of ultrashort laser pulse, and obtain high conversion efficiency simultaneously. The method for determining the chirp parameter which satisfies the chirp-matching condition is presented. The effects of the crystal length, the noise bandwidth, the pump chirp, as well as the synchronization of signal and pump pulses on the improvement of SNR are also analyzed by numerical simulation.

This work proposes a diagnostic method, which is based on two-photon fluorescence measurement, to study the temporal characteristic of a laser pulse undergoing filamentation in air. The results show that the pulse duration, chirp rate and beam radius could be retrieved simultaneously. This simple technique is useful in practice to trace the underlying dynamics of filamentation in air.

According to the elliptical birefringence in magneto-optic (MO) fiber, the eigen and non-eigen nonlinear coupled-mode equations for guided optical waves are put forward, which are used for analyzing nonlinear effects and elliptical birefringence in MO fiber. The relation between the equivalent nonlinear coefficient and the ellipticity of eigen elliptical polarized light is deduced for self-phase modulation (SPM) case. The maximum nonlinear phase shift of SPM will decline with the increase of magnetic field, and then reveals the mechanism of magnetically controlled nonlinear optical devices. Our calculation results show that the eigen nonlinear couple-mode equations are especially applicable for split-step Fourier method, and the polarization dependence of nonlinearity reduces under large applied magnetic field for input linearly polarized light. The findings can apply to the control of nonlinear effects in optical communication field.

Imaging velocity interferometer system for any reflector (VISAR) is an important diagnostic tool for various experiments involving laser-driven shock-wave propagation. On the basis of the imaging VISAR implemented at the Shenguang-Ⅲ prototype laser facility, a novel imaging VISAR system with a magnification ratio of 30 is proposed. Making use of the imaging VISAR, velocity of free surface and shock-wave traveling through transparent media can be measured. The main improvement is made due to the disadvantage of the former system. Details of the optical designing are also described. The design results show that the spatial resolution is better than 5 μm, and the whole system is more effective than the former.

With the development of aerospace technology, research of lightweight reflector is focusing on the mirrors with a larger radius to thickness ratio and higher lightweighting. However, when the surface accuracy of lightweight mirrors, such as PV values of below 0.1λ, mirror surface will obviously shows "imprinting effect" like the wave. The "imprinting effect" derives from the gravity and the pressure of polishing head has become a barrier for high-precision processing of lightweight reflector. It is mainly researched a new way that fills air into the inside of mirrors to resist the elastic deformation resulting from the pressure of polishing head. The simulation result shows that the immersion charge-method can eliminate the "imprinting effect", and the shape accuracy of mirrors is also much better than that caused by gravity.

Localized surface plasmon resonance (LSPR) spectrum behaviors of PMMA/Ag core-shell nanoparticles are extensively and systematically simulated by a calculation method based on Mie theory. Through the simulation calculation, the dependence of the LSPR behaviors of the core-shell nanoparticle on nanoparticle size, ratio of the radius of PMMA core to the thickness of Ag shell, and some other factors is studied. Furthermore, LSPR behaviors of Ag nanoparticles are simulated as well for comparison. The simulation results show that the nanosized PMMA dielectric core can weaken the retardation effects in the process of free electron resonance in the Ag nanoshell. Thus, compared with the LSPR of Ag nanoparticles, the position of the LSPR peak of the PMMA/Ag core-shell nanoparticles has an even more obvious red shift and the width of the LSPR becomes even narrower. Such simulation results indicate that the core-shell nanoparticles would have more advantages over Ag nanoparticles for potential applications of future chemical and biological nanosensors.

Within the accuracy of first-order Born approximation, the visibility of intensity correlated field is derived for two cases, i.e., the scalar and electromagnetic plane wave scattering from quasi-homogeneous (QH) media, respectively. Analytical results indicate that the visibility of intensity correlated field depends on the strength of scattering potential and the ratio D/R for the scalar case, where D is the radius of fiber-optic probe, and R is the distance between the scatterer and the fiber-optic probe. Comparably, for the electromagnetic case, the corresponding visibility relates with the strength of scattering potential, polarization of incident waves and the ratio D/R. Furthermore, numerical simulations are performed to investigate the influences of above parameters on the mean value of visibility. Numerical results further reveal that the strength of scattering potential of QH media may be determined by solutions of the inverse scattering problem provided that the visibility of intensity correlated field is obtained from experiments. The results may provide potential applications for the reconstruction and determination of unknown scatterer in optical coherence tomography and ghost imaging using the pseudo thermal light.

A passive nonlinear error compensation method is proposed for single-frequency laser interferometer. It is realized by changing the location of the wave plate in interferometer to adjust the polarization of the interferometer, which compensates the nonlinear error caused by the non-ideal performance and location of the polarized beam splitter, the depolarized beam splitter, the wave plates and other optical parts. A corresponding integrated interferometer nonlinear error on-line detection system is constructed. The experimental results show that the AC and DC output signal suppression ratio is greater than 500 and the nonlinear quadrate phase shift m is reduced to 0.003 rad (0.15 nm). Through stability measurement experiment in 24 h, m changes within the range of 0.024 rad (1.21 nm), which demonstrates the effectiveness of the method in greatly inhibiting nonlinearity.

The quantum bit error rate (QBER) caused by time jitter in the phase-coding quantum key distribution (QKD) system is analysed. The physical model of the relation between the QBER and the time jitter in the phase-coding QKD is proposed. The formula between the general waveform function of the single photon pulses and QBER is given. Based on the distribution of Gaussian pulse, the quantitative relation among QBER, the pulse width and the distribution of the time jitter is educed, based on which the QBER of a certain time jitter distribution can be calculated in the Gaussian single photon pulse. The method of reducing the QBER by the control of the system′s time jitter and the width of single photon pulse is proposed.

The W state of three two-level atoms, two of which are separated into two initially empty coupling cavities, is considered. The temporal evolution in the entanglement between the atoms, between the cavities, as well as between the atom and the local cavity mode is numerically studied. Through comparing the results if a direct selective measurement is performed or not, the influences of state-selective measurement of the atom outside cavities on entanglement are investigated. The influences of cavity-cavity coupling coefficient on the entanglement is also investigated. The results show that the entanglement can be strengthened through the state-selective measurement on the atom outside the cavities.

A new high resolution reflecting scanning Fourier transform spectrometry produces nonlinear optical path difference (OPD) by rotating two tilted plane mirrors. OPD plays an important role in evaluating the performance and parameters and designing the spectrometry. Based on analyzing the principle of this reflecting scanning Fourier transform spectrometry, we adopt two methods to study OPD. One method is conventional tracing rays method by tracing rays following the Malus law, the other is novel point-image method by using mirror imaging principle and computer simulation to calculate OPD. The general expression of OPD with time change is deduced by the tracing rays method, and factors associated with the change of OPD are pointed out. Factors and their weights on the maximum OPD are also discussed. The calculation results demonstrate that OPD is closely related to the spatial distance between the primary rotating mirror (PRM) and secondary rotating mirror (SRM), the tilted angle between rotating mirrors′ plane and the plane perpendicular to rotational axis, and the incident angle between incident beam split from beam splitter and the rotational axis. Also, it is proved that the tracing rays method and point-image method are both feasible and efficient; and the simulation curves of them agree with each other.

The Tm3+/Yb3+ codoped bismuth germanate glass substrates containing metal Ag nanoparticles (NPs) were synthesized by the conventional melting-quenching technique. The absorption band related to the surface plasmon resonance (SPR) of the silver NPs is located from 556 to 581 nm. Transmission electron microscopic image clearly reveals homogeneously dispersed Ag NPs with the size from 5 to 25 nm. The upconversion luminescence spectra in the range of 400~900 nm are measured. The upconversion mechanism of Tm3+/Yb3+ codoped bismuth germanate glass is also discussed. Upconversion luminescence exhibits three main emission bands of Tm3+ ions centered at 476 nm (blue), 649 nm (red) and 801 nm (near-infrared) due to 1G4→3H6, 1G4→3F4, 3H4→3H6 transitions, respectively. With the addition of the AgCl up to mass fraction of 0.2%, the intensities of these emission bands increase by 18.1, 8.3 and 6.4 folds, respectively. The enhancement of upconversion emission is attributed to the enhanced local field induced by Ag0 SPR and energy transfer from Ag0 to Tm3+ ions.

A homogeneous model for extracting the optical constants of a weakly absorbing film, which is based on the envelope of the transmittance spectrum, has been developed. Expressions are given to correct the spectrum measurements of the thin film to eliminate the effects due to the reflectance from the rear surface of the substrate. Moreover, a simple approach for determining the optical constants of the substrate is also described. For a LaF3 film deposited on CaF2 substrate by Mo-boat evaporation, the optical constants of the as-deposited and ultraviolet (UV)-treated 40 min LaF3 films and CaF2 substrate in the wavelength region from 160 to 340 nm are obtained. The experimental results indicate that UV-treatment can improve the optical properties (increase the refractive index and reduce the extinction coefficient) and reduce the physical thickness of the LaF3 film.

The irregularly shaped distributed Bragg reflector (IDBR) for thin film solar cell is designed according to the theory of multi-beam interference, contains two pairs of α-SiH(36.5 nm)/SiO2(81 nm) distributed Bragg reflector (DBR) and three pairs of α-SiH(73 nm)/SiO2(162 nm) DBR. Different structures of back reflector are discussed. The criterion to choose the central wavelength and pairs of DBR is analyzed. The method of iteration is used to calculate the reflectivity. The IDBR is fabricated by plasma enhanced chemical vapor deposition (PECVD) on a silicon wafer. The experimental result shows that the average reflectivity of IDBR is 87% in the spectral range of 420~1400 nm, and is as high as 91.6% from 600~1300 nm. The result indicates that this design has the potential to enhance the light absorption for thin film solar cells in broad band.

The color of cyan, magenta, yellow, black, orange and green are used as printing primary colors. The six-color separation model is established based on color subarea theory. Based on the spectral measurement data in an existing six-color printing International Color Consortium (ICC) profile, the Neugebauer equation system in each subarea is established. The gamut compression algorithm based on the node addresses is introduced into the solving process of the Neugebauer equation system in each subarea based on Newton-Raphson method. It successfully solves the problem that the color separation of sampling points outside the target gamut results in the abnormal value. The corresponding six-color ICC profile based on the new color separation model is generated. Subjective evaluation method is used to design the evaluation experiment. Through the longitudinal and transverse evaluation experiments, it is concluded that the proposed six-color separation algorithm and multi-color separation algorithm of mainstream color management software have similar precision. The performance of the separation algorithm can be improved further by perfecting gray component replacement experiment and the correction of Neugebauer equations.

The iridescent blue color of Morpho butterfly can be found from far. This is a typical structural color, mainly caused by several elementary optical processes with the ordered arrays of micro/nano structures including multilayer interference, diffraction grating, light scattering, etc. A general design tool based on the rigorous coupled-wave analysis (RCWA) for diffractive optical structures is employed to construct a two-dimensional model that mimicks the wing scales. The influence of the structural parameters on optical properties is systematically analyzed, including the horizontal duty ratio of the bottom dielectric element, the width difference of the adjacent dielectric elements, the vertical duty ratio of the dielectric element, and the angle between the spine and the base. The mechanism of the structural color is then revealed. The results can be used to steer the design, manufacture and applications of the bionic micro/nano structures/devices for environmental detection.