In view of the world＇s ever-increasing demand for energy, limitation of usable fossil fuels and the impact of large exhaust pollutant on the environment during their use, there is an urgent need to exploit new energy sources that are plentiful, renewable and clean. This paper introduces briefly energy source technologies now available, centres on the analyses of direct utilization of solar energy, solar cells and the decomposing water by solar energy from the optical and optical technological point of view. Direct utilization of solar energy can be expanded through a system of tracing and focusing sunlight with simplicity and low cost in combination with the heat-resisting, broad band transmissive, low-loss and inexpensive hollow-core plastic fibers. In solar cell field, the stress should be put on the research for various film solar cells except for improving the efficiency and reducing the cost for crystalline silicon solar cells. In decomposing water by solar energy, in order to obtain hydrogen, the stress should be put on the research for decomposing water by light catalysis. By means of transforming solar radiation spectrum into brightness maximum to be located in infrared region by using the cavity radiator, the most spectra can be absorbed by water, and which provides a new technological way to be probably worthy of exploration.

A closed-loop adaptive optics system, which consists of a 20-element bimorph deformable mirror and a Shack-Hartmann wave-front sensor with 13×13 sub-aperture arrays, is established to test the spatial fitting capability to 3～20 Zernike items of the bimorph deformable mirror. Constrast is made between experimental result and simulation result. And the effect of mismatch between bimorph deformable mirror and the sub-apertures of Shack-Hartmann sensor is analyzed. Results show that most of the fitting errors of 3～20 Zernike items are smaller than 0.5, and the mean difference between experiment and simulation is smaller than 0.1. Compared with rigorous aligned ideal situation, the fitting error gets lager with the increase of mismatch size. The effect of mismatch is more serious for higher order aberrations than the lower ones.

The principle of an adaptive optics (AO) system with two sets of wavefront correctors for all-path aberration correction is analyzed. The measured wavefront information by two sets of Hartmann-Shack wavefront sensors is fused, and the optimized formula of the aberrations corrected by two sets of wavefront correctors is deduced. The performance of the AO system with two sets of wavefront correctors for all-path aberration correction is simulated. The result is compared with that of the AO system with a single corrector. The simulation result indicates the formula is right and the two sets of wavefront correctors can be decoupled. The correction performance is the same as that of AO system with a single deformable mirror with ideal stroke.

Based on the data of underwater light field measured in Taihu lake and Tianmuhu lake, on the supposition that there is source-free and no inelastic-scattering water, the inherent optical property (absorption coefficient) of medium in shallow lakes was successfully inversed by using the profile of upward and downward irradiance, diffuse reflectivity and diffuse decay coefficient.The error aroused from surface wave and ship shadow was reduced by the inversion method. The inversion results agree well with that by using the quantitative filter technique (QFT). The method is helpful to research on photosynthesis available radiation distribution among different media and aquatic ecology responding to underwater light field, to mechanism of cyanobacteria bloom and to remote sensing precision for case 2 water improved.

The retrieval of aerosol optical properties and surface albedo based on the POLDER are proposed. POLDER provides the multi-angle data of polarization and radiance of solar radiation reflected by the earth atmosphere-surface system in the visible and near-infrared wavelengths. An algorithm that estimates the aerosol optical properties based on combining radiance with polarization is developed. A look-up table (LUT) is built which is compiled based on doubling-adding vector radiative transfer mode in an atmosphere- ground system. The clouds mask, absorbing gas corrections and stratospheric aerosol correction are considered during the process. Aerosol characteristic and the surface albedo are estimated simultaneously based on comparison of measurements by POLDER with the numerical values of 865 nm band stored in LUT. The obtained results were validated with the POLDER aerosols products supplied by CNES. The retrieval results of aerosol optical properties and surface albedo show that the algorithm is valid.

The transmission characteristics of an excited-state Faraday anomalous dispersion optical filter （ESFADOF） operating on the 5P1/2→10S1/2 transition (532 nm) in a rubidium vapor cell are analyzed and discussed theoretically. The theoretical model of ESFADOF based on quantum-mechanical perturbation theory and quantum transition theory in the intermediate field is presented. The theoretical results show that the vapor cell operates in an optimal working condition when the laser pump intensity is 20 W/m2 and the rubidium cell (0.1 m in length) temperature is 434 K in an axial magnetic strength of 0.067 T, and the anticipated performance in the line-center operation has been obtained. The transmission spectrum with a higher transmission peak in the line center that is more suitable for a signal light channel is shown. This model predicts that a peak transmission is near to 50% with an equivalent bandwidth of only 2.6 GHz. The spectral properties of the presented Rb-ESFADOF at 532 nm may be used to detect the practical and important frequency-doubled Nd:YAG laser.

The collinear interaction between incident linearly chirped Gaussian pulses and single-frequency continuous microwave magneto-static surface waves (MSSW) in a horizontally magneto-optical film waveguide is studied and the coupling equations between optical pulses and MSSWs are presented, which can be used to analyze MSSW-based optical pulse signal processing. The diffraction characteristics of incident linearly chirped Gaussian pulses at 1310 nm and 1550 nm wavelength are in detail analyzed by the analytical and numerical methods respectively, and the same results are obtained. It is shown that, the full width at half maximum (FWHM) of diffracted optical pulses can be reduced by using a larger slope of phase-mismatching distribution or an incident optical pulse with large chirp parameter. The diffracted optical pulse corresponding to the 1310 nm carrier has a larger peak intensity, while the 1550 nm optical pulse is much more easily compressed for the case considered here. The influence of magnetic loss on output pulse intensity and pulse width is analyzed. For an ordinary magneto-optic (MO) film, the pulse compression effect is not basically affected by magnetic loss.

A novel fiber-optic Fabry-Perot refractive-index sensor is proposed, which is formed by a section of endlessly single-mode photonic crystal fiber (EPCF) and conventional single-mode fiber. The theoretical and experimental results show that the refractive-index measurement based on the fringe visibility is independent of temperature change, and the refractive-index resolution and sensitivity are about 2×10-5 and 4.59/RIU, respectively, when the refractive index of the environment is in the range of 1.32～1.44. In addition, such a sensor can be used as an excellent temperature sensor with a cavity-length-temperature sensitivity of 18.72 nm/℃ with temperature ranging from 20℃ to 100℃. Therefore, simultaneous measurement of refractive index and temperature can be realized by determination of the fringe visibility and the cavity length change of such anEPCF-based IFPI, respectively. It provides a practical way to measure refractive index with self temperature compensation.

2008-04-07

The performances of colour-difference formulae were investigated for predicting very large colour difference based on visual evaluation of object surface colours. The experiment of psychophysical visual assessment of 60 sample pairs with ratio judgement was carried out on 18 observers. The evaluation data of visual colour difference were btained. The data were used to evaluate the two common colour-difference formulae, CIELAB and CIEDE2000, and the two latest CAM-based colour-difference formulae, CAM02-UCS and CAM02-LCD. The detailed comparison and analysis indicated that CAM02-UCS and CAM02-LCD outperformed others for very large colour difference. In addition, the experimental data were employed to test the power law model proposed by Attridge et al. and the consistent result was obtained.

Sharpening is a key technology of infrared image enhancement, but the image’s noise will be enhanced because of the sharpening, and the signal-to-noise ratio will decrease. The algorithm is researched to sharpen the image without increasing the noise. The distribution difference between random noise and the real edge is analyzed, and the definitions of the membership and the probability relaxation are advanced to distinguish the illumination changes caused by real edges or noise in the infrared image. An algorithm based on the two methods are introduced. Different from the tranditional algorithms, this algorithm considers the spatial difference between the real edge and the noise. So this algorithm not only enhances the details, but also reduces the enhancement of random noise. As it is shown in experiments, the edge of the image is sharpened and the noise is suppressed. This algorithm has practicality and potential application value in the field of infrared images contrast enhancement.

A new phase unwrapping method based on qualitymap-guided path-integralmethod is presented to deal with the discontinuous unwrapping result of the interferogram with obscurations in phase-shifting interferometry. First, the obscured regions are filled according to the texture feature of wrapped phase data in adjacent valid regions by image repair. The valid regions are connected together in this way and thus path-integral phase unwrapping can be conducted through different valid regions. To ensure the same addition or subtraction of integral multiple of 2π between wrapped phase in the same fringe order but different valid regions, a path-integral phase unwrapping method based on a new quality map is proposed. The new quality map can lead the integral path to follow the minimum phase variation direction through the filled regions. The unwrapping result shows that, the presented method is effective to avoid the global error of integral multiple of 2π between different valid regions in phase unwrapping of interferogram with obscurations in phase-shifting interferometry.

A method based on stationary wavelet transform using tensor for infrared image denoising was proposed. The noisy infrared image was decomposed by stationary wavelet transform. The low frequency approximation image was not changed. A cube was constituted by the high frequency sub-band images at horizontal, vertical and diagonal directions of the whole scales. And a third-order tensor was formed. The signal wavelet coefficients were estimated by multi-linear algebra method. The space structural relations of wavelet coefficients were not destroyed in this way. The correlations of coefficients both inter-scale and intra-scale were considered at the same time. The wavelet coefficients which were estimated in this method were better than the linear minimum mean square-error estimation (LMMSE) method. The denoised image was obtained by inverse stationary wavelet transform using the low frequency approximation image and the estimated high frequency detail images. Experiment result shows that the denoising results were better than the traditional LMMSE estimation with stationary wavelet domains in performance evaluation and visual quality. And a new thought was provided to estimate the wavelet coefficients more accurately.

An improved cylindrical panoramic image automatic mosaic algorithm based on phase correlation is proposed. Firstly, the cylindrical projecting formulae are given. Then, the normalized cross-correlation function is computed, and the peak value and position of the normalized cross-correlation function are found. The peak value is used to estimate whether two images are overlapped. The first and the last image can be ascertained automatically by maximal correlation degree intersecting, and the relation of the overlapped images can be ascertained by the peak position. Finally, the rounding planar image sequences are projected to cylindrical coordinate, and the cylindrical panoramic image can be gained by stitching together the images in sequence with the calculated transformation parameters. Experimental results show that the proposed method outperforms traditional methods with high robustness and precision, which can sort the unordered image sequences and stitch the images in sequence into a cylindrical panoramic image effectively and automatically.

In order to overcome the problems that vein lines are inaccurate in results of existed segmentation algorithms caused by the uneven illumination of the vein image, a novel image segmentation algorithm based on maximalson intra-neighbor difference(MIND) is proposed. In the algorithm, the neighbor information of original vein image is well used to get the MIND image together with a new distance function. The enhanced image is got by adding with original image processed by histogram modification. Through the calculated mean image of enhanced image and weighted comparison with enhanced image, segmentation result is obtained. During the segmentation, to the segmentation result can be improved by adjusting key parameters adaptively according to the histogram of MIND image. Experimental results demonstrate the effectiveness of the proposed algorithm.

In order to investigate the dependence of lightness, chroma, and hue visual tolerances upon hue angles in CIELAB color space, five hue circles were selected at different lightness and chroma levels (L*=30, 50, 70 and C*ab=10, 20, 30), which were observed using three visual scales (ΔV=3.02, 5.92和8.87 CIELAB units). The test stimuli were presented on the CRT, and the corresponding lightness, chroma, and hue tolerances were measured by a panel of 8 color-normal observers by using the psychophysical method of constant stimuli. Based on the obtained correlation between visual tolerances and hue angles, the prediction performances of the six CIELAB-based color-difference formulae, CIELAB, CMC, BFD, CIE94, LCD, and CIEDE2000, were further evaluated. The detailed analysis indicated that due to the independence between the lightness tolerances and the hue angles, all the formulae performs well, with CIEDE2000 a little better than the others. For chroma tolerances, LCD performs the best, while CIEDE2000 and BFD the poorest, and the others performs nearly the same. The hue weighting functions of CIEDE2000 and LCD outperforms others obviously, with CMC performing poorest.

In the application of 3D data visualization, demands on insight into the inner region-of-interest (ROI) of volume are often made while keeping the outer tissue visible. However, a better effect is usually achieved after 3D data has already been preprocessed. In this paper, according to the traditional optical model of volume rending, an interactive optical model is deduced. The calculations on the transmitted light effect of 3D data are introduced in the classifying information. And a perspective ray model based on inner region of interests is constructed. In this model, a better perspective effect is gotten without any preprocessing while keeping the outer tissues semi-transparent. The experiment proves that this method produced a more intuitive result than the traditional model together keeping the frame rates greater than 20 f/s. Using this model, the ability to recognize the feather of 3D data is improved and the theoretic supports are provided for the effective analysis on 3D data.

Ring artifacts in computed tomography (CT) images are introduced by detector element’s response nonuniformity. Ring artifact degrades the quality of CT image, influences the determination of defect, and hampers post processing and prohibiting quantitative analysis. Two algorithms for ring artifact correction are proposed based on feature recognition and B-form of the spline curve fitting. The former is for the situation that the response of a single detector element or few continuous detector elements is obviously nonuniform. According to the algorithm,the position of the detector element whose response is nonuniform is determined. And a local median filter is executed at the position to depress the vertical streaking in the sinogram.The latter is for the situation that many continuous detector elements’ response has small nonuniformity. In this method, the normalized gain factors of the detector elements are gotten through B-form of the spline curve fitting . So detector element’s response nonuniformity can be corrected. The two algorithms have their own characteristics which supply each other and compose together a complete ring artifact correction system. The feasibility of the two methods is validated by the experimental data.

In order to improve contrast and resolution in photoacoustic tomography (PAT), the filtered photoacoustic (PA) signal of tissue phantom was often deconvoluted by transducer impulse response to restore its spectrum. Because the cut-off frequency of band-pass filter was determined manually, it couldn’t suppress noise effectively, it was hard to get static deconvolution result. To solve this problem, a Wiener filter deconvolution algorithm was presented. The transducer impulse response was measured by a point photoacoustic source. The noise was suppressed by Wiener filter during deconvolution. The filter’s parameter was estimated by discrete wavelet transform (DWT). The photoacoustic image was reconstructed by time domain back projection algorithm. Both numerical simulation and experimental results demonstrated that the noise was suppressed effectively during deconvolution. The imaging contrast and resolution was improved.

Modulation measurement profilometry is a vertical 3D measurement technique, which can measure the complex objects with acute changes in their surfaces. A fast modulation measurement profilometry based on orthogonal spatial carrier is proposed. In this method, two cross-sinusoidal gratings at a certain interval are imaged on the surface of the testing object which is laid between two imaging planes of them. We can separate the images of orthogonal gratings through spatial frequency domain filtering, obtain the modulation distribution images of two cross-sinusoidal gratings, and then restore the height of the object through the map of the ratio of modulations and the height. It is convenient to obtain the height using only one captured image, so the main characteristic of this method is real-time 3D information collection. The experimental result proves that it can restore the height of the object fast and more accurately.

Laser speckle imaging technique, based on laser speckle contrast analysis, is a full field optical imaging method which does not need scanning. It is getting increasing use in monitoring dynamic fluctuation of blood flow in tissues in physiological and pathological situations. In practice, various factors such as averaged image speckle size have impact on speckle contrast, making the accuracy of this technique affected in reflecting blood flow changes. This study investigates the impact of averaged image speckle size on statistical characteristics of image speckle pattern by simulating image speckle pattern. The quantitative relation between imaging parameters and averaged image speckle size is analyzed. The results are finally validated by phantom experiment. These results confirm the reasonable formula for calculating averaged image speckle size and the phenomenon that speckle contrast increases with increasing averaged image speckle size, providing a basis for determining reasonable imaging parameters.

A method for ray tracing and wavefront reconstruction is presented based on the structured light imaging. The phase information is carried in the fringes of structured light. The phase changes in the imaging process can be tested accurately by the phase-shifting technique and then used for ray tracing to get the spot diagram. The wavefront can be reconstructed because of the light traveling in direction normal to wavefront. A liquid crystal display (LCD) is illuminated behind a point light source, which displays the sine intensity-modulated patterns. The standard fringe beam is deformed when it travels through the tested lens. A CCD camera detects the deformed fringes and evaluation of the tested lens is done by the fringe analysis. The use of a computer display generation leads the flexible adjustment of period and direction of the patterns and accurate phase shift. The experiment confirms the feasibility of this method.

A precise measurement method for three-dimensional coordinate of points’ larger than ten meters in field working space is presented. And the problem that the mosaic precision of cell measuring data is very low in large three-dimensional free-form measurement is solved simultaneously. Measuring pictures of visual characters called global control points at determined points are taken by special metrical camera. After processing the pictures using high precision image processing technique, automatic matching technique of global control points and ray bundle adjustment technique, the three-dimensional coordinates of global control points are retrieved. Experimental results show that the method can attain relative accuracy about 0.073% by using common digital camera and can be accomplished flexibly, freely, rapidly and accurately.

A new method of measuring thickness of optical thin film with dispersive white-light spectral interferometry is proposed. By analyzing the recorded interference spectrum in the frequency domain and fitting the recorded channel spectrum to the theoretical value, the thin-film thickness can be determined. The thicknesses of several different thin film samples are calculated and the results show that this method can reach high precision with the error less than 1 nm. The new method can provide a simple and fast solution in calculating thickness of optical thin films, compared with traditional spectrophotometric and ellipsometric method, while still maintaining high accuracy.

The principle of measuring nonlinearity of ultraviolet photodetector and power meter at 266 nm was presented in this paper. A new technique is proposed for measuring the nonlinearity of ultraviolet photodetector using the power superposition method. The facility of accurate measuring ultraviolet photodetector nonlinearity has been developed. The power nonlinearity dynamic range is widened by using a polarizing beam splitter cubes for beam splitting and combining. The effect of background and scattering signals on the measurement results is reduced by the light shield. The measurement uncertainties are reduced by automatic test programme and optimized model. Results show that in the power range of 1 nW～100 μW, the repeatability of the results is better than 0.3％ and the typical expanded measurement uncertainty of nonlinearity is less than 0.8% (k=2).

A tunable S-band fiber ring laser is demonstrated, and the dependence of output power’s on the lasing wavelength and the pump power are experimentally researched. Stable output is obtained with the tuning range of 1482.73～1520.75 nm, the 3 dB bandwidth narrower than 0.03 nm and pump power of 113 mW by tuning an all-fiber tunable Fabry-Pérot filter. In the range of 1487.70～1520.75 nm, the output power exceeds 5 dBm and the side mode suppression ratio (SMSR) is larger than 60 dB. A maximal output power of 7.11 dBm is achieved at 1499.02 nm, together with a fluctuation below 0.04 dB during 900 s.

In order to solve the problem of the slow decision speed of the Support Vector Machine (SVM) due to not sparse enough in the application of Inertial Confinement Fusion (ICF) experimental targets recognition, Relevance Vector Machine (RVM) is proposed to recognize the ICF experimental targets. A multi-classification RVM based on the binary tree is designed. For getting a more reasonable binary tree structure, both the class distance and class distribution are considered in the construction of multi-classification RVM. Experiments show that the comparable classification accuracy of RVM and SVM is all square, as well as much faster decision speed due to higher sparsity. This multi-class recognition algorithm exhibits superiority in mixed classification accuracy comparing to the traditional methods such as ‘One Against One’, ‘One Against Rest ’,‘Directed Acyclic Graph’ and ‘Binary Tree Based On Class Distance’.

The theoretical model which transverse magnetic (TM) polarization state and transverse electric (TE) polarization state share the same inverted population is built based on the time dependent theory of random lasers. By using the finite difference time domain (FDTD) method to numerically solve Maxwell equations and rate equations, we can obtain the threshold properties for two polarization states. The results show that TM state has a lower lasing threshold than TE state when they don’t share the inverted population, otherwise, the TM state is strongly suppressed. In the competition condition, the threshold for two states changes hardly by changing the surface-filling fraction, but will decrease for TM state when increasing the sample size.

A 400 Hz repetition rate, 1.52 W average power diode-pumped all-solid-state narrow linewidth sodium guide star laser was reported. Two acousto-optic Q-swithed 1064 m and 1319 nm lasers were used as basic-frequency lasers and they generated 589nm sodium guide star laser through a extra-cavity sum-frequency generation(SFG) LBO crystal. The master-slave drivers mode and the electronics delay compensation technology were employed to make the two Q-pulses time-synchronization. The conversion efficiency of SFG was about 25.1% and the electro-optical efficiency was 0.32%. To lock the central wavelength to the sodium D2a line,an etalon with water cooling was inserted into the 1064 nm oscillator.The central wavelength finally aimed at 589.159 nm(error less than ±1 pm) by tuning the temperature and angle of the etalon.

Near the damage threshold, the periodic surface structure on pure Cu, Ag and Au produced by femtosecond laser pulses of 60 fs at 1 kHz repetition with the central wavelength of 800 nm is observed by scanning electronic microscope （SEM）. With the number of laser pulses increasing, the structure is damaged obviously. The period of the structure depending on the incidence angle is studied, and it is found that the period of the three metals are almost the same when the incidence angle is small. The difference between each other is still infinitesimal when the incident angle is large. Different metals have different damage threshold, so it is believed that the incident laser energy density at small angle affects the periodic structures’ sharpness only. It was verified in terms of surface periodic structures theory (SPSs).

Nd-doped phosphate glass, quartz and BK7 are the main optical material useds in laser inertial confinement fusion（ICF）equipment. In Experiment, these three type glass were separately polished used polishing slurry with different average particle size. The relation of material remaval rate and average particle size was studied. Experiment indicates that special glass, for its typical physical and chemcal property, need corresponding average particle size of polishing slurry to get optimal polishing material removal rate. The influence on roughness of different slurry particle size for these three type glass is studied in experiment. Experiment data shows that the influences on roughness caused by slurry particle size are different for different glasses.

Nano europium oxide cyclohexanone colloids were prepared by pulsed laser ablation of the Eu2O3 target submerged in flowing liquid containing cyclohexanone and phthalic anhydride. The colloids were characterized by fluorescence spectra, fluorescence lifetime, high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SED). The results show the nanoparticles in the colloids have the structure with Eu3+ ions located in the core and Eu2+ ions at the surface of nanoparticles. Phthalic anhydride coordinates to the surface europium ions and reduces Eu3+ ions to Eu2+ ions. Phthalic anhydride and cyclohexanone can absorb UV radiations and transfer the energy to the surface Eu2+ ions; and then Eu2+ ions emit violet fluorescence with intense emission peaks at 415 nm and 465 nm, respectively, which can be ascribed to the lowest 5d-4f transition of Eu2+ in europium oxide nanoparticles.

The dye 2,7-dimethyl-3,6-diazacyclohepta-1,6-diene perchlorate was prepared by condensation reaction and characterized by elemental analysis, infrared spectroscopy and UV-visible techniques. The influences of dye solution and dye-doped polyvinyl alcohol (PVA) film with different concentrations on the property of UV spectroscopy were mainly investigated. Optical transmission spectra indicate that maximum absorption peaks for dye solution and dye-doped PVA film feature at 322 nm and 325 nm, respectively. With increasing dopant concentration, dye solution and dye-doped film exhibit strong absorption at cut-off region (285～345 nm) and are high transmissive at solar blind spectral region (240～285 nm). The sample composed of dye solution or dye-doped film, inorganic crystal and coloured glass as solar blind filter was demonstrated.

Transmission spectra characteristics of one dimension (1-D) photonic crystal (PC) with nematic liquid crystal (NLC) are investigated theoretically and experimentally. Transmission spectra of 1D PC with NLC under different applied voltage were obtained in experiment . With the voltage range from 0 V to 10 V, it shows that relative transmittance of transmission peak is from 48% to 18%, range of photonic band gaps (PBG) is 290 nm, tunable range is 88 nm, full width at half maximum (FWHM) of the transmission peaks is 7 nm. Theoretical result is closed to experimental result comparatively. These properties can make 1-D PC with NLC be applied to tunable optical filters or optical switches.

A single layer of silica beads was embedded into polystyrene by combining a self-assembly method with spin-coating technique, a photonic colloid structure with a planar defect was got in the research. After the infiltration of silica and removal of polystyrene and calcination, an inversed structure with planar defect was obtained. The optical transmission spectra both in the opal and inverse opal structures indicates that the position of the defect state has red shift when the diameter of beads becomes larger whenever there is a defect layer or not, otherwise the smaller diameter has blue shift. But when there is a defect layer and the diameter of beads is changeless, the position of the defect states has blue shift in a reduced-index defect, and the position of the defect states has red shift in an increased-index defect. The transmission spectra structures can also be adjusted by other factors, such as the thickness of defect.

In quest of the most simple and effective treatment for in vivo skin experiments, thiazone was used as an enhancer in our study. To compare with the pure polyethyleneglycol 400 (PEG400) solution, the mixed solution (thiazone in combination with) was applied on the stratum corneum partly removed skin and intact skin respectively. For visual observation, photographs of the local skins were taken by CCD; and then the light reflectance spectra of skin were monitored. The results showed that a mixed solution could make the skin without stratum corneum more transparent in 15 min, with the reflectance spectrum decreased significantly; while there’s no observable change in the intact skins. However, the pure PEG400 did not have optical clearing effects on any skins. In conclusion, the non-invasive drug delivery method, which is combined with physically abrading part of the stratum corneum and adding chemical enhancer-thiazone, can improve the effect of PEG400 in skin optical clearing quickly and effectively.

The propagation of polarized light in anisotropic medium like some fibrous tissues (e.g., muscle, skin, tooth) is investigated with Monte Carlo method. In the simulation, the myofibrils and collagen fibers are approximated as long cylinders and the tissue phantom is composed of spherical and cylindrical structures. We present the realization and validation of Monte Carlo program, and then apply the program to simulate and analyze polarization imaging process of muscle. The good agreement between the simulation results and the experimental results validates the assumption of the phantom composition and shows the feasibility of Monte Carlo method. This paper also presents how to describe tissue anisotropy according to two parameters derived from the polarization imaging.

The steady-state solutions and eigenvalues of the nondegenerate optical parametric oscillator are obtained, and the instabilities of the system in both cases of resonance and non-zero detuning are investigated. The results show that the system is always in a steady state when there is resonating and it has instability when there is non-zero detuning. The evolution of eigenvalues versus input field amplitude portrayed by numerical simulation with no detuning, as well as the evolution of the three output modes versus time with non-zero detuning, are proposed.

In recent years, researches about the controllable group velocity of light propagation had made many progresses. The mechanism of the generation of slow and fast light, as one of the most important aspects in the research of slow and fast light, had attracted great interest in researchers. In this letter, the authors described a simple experiment for the tracing of light signals in erbium-doped fiber (EDF) at the optical communication wavelength. We have, directly, observed the evolution of slow and fast signals with different waveforms that travel in EDF. Through tracing the wave evolution, when slow light (0<vgc, c is the speed of light in vacuum, vg is the group velocity of light) or fast light (vg<0) was got in EDF, we concluded that asymmetrical absorption and amplification on the periodical signal could account for the generation of slow and fast light in EDF.

Pulse compression grating plays very important role in the laser confinement fusion system. Along with the development of laser confinement fusion project, more and more large aperature gratings are needed. Holographic technology is very important means to manufacture large aperature gratings, but the aperature of gratings is limited by the recording system. In order to create large aperature pulse compression grating, the method by several times exposure to fabricate large aperature mosaic gratings is investigated in this paper. The method use a reference grating as a detecting devices to test the phase matching situation between the recording light wave and the recorded grating. By using stripes locking system to control the phase of light wave, the goal of manfacture large aperature compression mosaic grating will be achieved. At last, the mosaic grating experiment is studied. The grating frequency is 1740 lp/mm and the alignment accuracy is better than 30 nm.

Depolarization is a main paramenter of the depolarizer. In order to improve the performance of the double plate rotation depolarizer, the average Mueller matrix is used to derive the theory expression of depolarization. The relationship between depolarization-polarization and related parameters is propased by using the average Mueller matrix and Stokes vector. Through the first order Bessel function solution, a satisfactory explanation of the depolarization for the depolarizer in theory is gained. Depolarization is related to some parameters such as the wavelength, the beam diameters the structural angle etc. A digital simulation is performed based on Matlab software. The theory results show that the shorter wavelength depolarizers is easier, depolarization effects improve when inereasing pupil radius or angle structure. Theoretical results meet well with the experiment. The discussions can supply theoretical basis for the design, production and use of the depolarizer.

A method to calculate the aberration of the reflected beam of corner cube retroreflector(CCR) is introduced. The light beam which passes through a faulty CCR will be induced an additional optical path difference, thus the characteristic of the phase of the reflecting beam and the direction of the beam propagation are changed. Using ray trace method, an effective mathematical model is built to calculate the additional aberration caused by dihedral angle errors and curved reflecting surfaces, and the error of the model is also analyzed. On conditions that the dihedral angle errors is 1″ and f-number of the reflecting surfaces is less than 0.5, the numerical simulation of the model shows that the additional aberration has a great centrosymmetry and the mean slop coefficient of the additional phase versus the phase introdured by the incident beam is zero, this characteristic is independent of the type and magnitude of fabrication errors. The aberration model of CCR offers a new way to analyze the system error caused by CCR. In addition, it would provide helps in manufacture of CCR for specific purpose.

A new refractive index fiber optic sensor with low cost, easy operation and the capability of multipoint parallel measurement is explored. A splitter is used in the refractive index fiber optic sensor to achieve multipoint parallel measurement. A high stable amplified spontaneous emission light source and three optical power meters are used as broadband source and detectors, respectively. A simple model is established, and the relation between the ratio of the light power carried by the core versus the total light power of a fiber and the external refractive index (RI) is analyzed in detail. In the experiment, the transmission losses of sample solution with different refractive indices are measured, the calibration curve between transmission loss (TL) and RI by comparison is obtained. It is found that the higher the RI is, the bigger the TL is. The experiment verifies that it can improve the system sensitivity greatly by introducing a fiber Bragg grating.

Regarding the liquid crystal phased array component of radar, how to select a certain amount scanning angles so as to satisfy the conditions that the light-beams of all scanning angles can cover the field of view and meet the scanning index is a brand-new problem. This paper proposes a method of scanning angles screening based on the beam-steering model of binary grating. In the method, the scanning angles are obtained by using a traversal algorithm. The beamsteering model of binary grating is used to steer the light beam and the uniform coverage of the field of view, maximum sidelobe level, diffraction efficiency are regarded as constraint conditions of scanning angles screening. The simulation results from Matlab show that the method is effective and feasible.

Red, green, and blue emissions with high efficiency and high color purity are essential for achieving full color displays. Relative to red and green emissions, blue-emitting materials have poor color purity and efficiency. Introducing microcavity structure into organic light emitting device (OLED ) can improve the color purity and properties of the device. The microcavity structure of blue light OLED (MOLED) was optimized. MOLED was fabricated and studied with a structure of Glass/DBR/ITO/NPB/ DPVBi/Alq3/LiF/Al. Comparing the optimized microcavity (MOLED) to the noncavity devices (OLED) under the same current density, the electroluminescence (EL) peak intensity of the MOLED increased 5.4 times, the spectrum integral intensity increased 33%, while the full width at half maximum (FWHM ) decreased 4.4 times (only 16 nm), the maximum luminance of 8439 cd/m2, maximum luminous efficiency of 2.4 cd/A, and peak at 472 nm and the CIE coordinates (X=0.14, Y=0.10) were obtained in MOLED. It shows that MOLED can improve not only the color purity, but also the properties of the device. The microcavity effects such as spectra narrowing and intensity enhancement of spontaneous emission have been observed for MOLED.

Balanced and unbalanced Mach-Zehnder interferometers were developed using two photoresist gratings fabricated on slide glass substrate. One grating served as the beam splitter and the other as the beam recombiner. A laser beam was incident on the first grating to produce multiple diffracted beams. The balanced interferometer used two mirrors to reflect two symmetrical diffracted beams onto the second grating, making the two patterns diffracted by the second grating completely superposed. The phase difference between the two components of one of the superposed beams was measured with a photodetector. For the unbalanced interferometer, only one diffracted beam was reflected upon the second grating, producing a diffraction pattern that completely overlaps with that from the zeroth-order beam. Performance of the unbalanced interferometer was investigated by using a 50 μm-thick glass plate to induce the phase difference.

In this paper, a theoretical model of the novel all-optical polarization switch based on nonresonant Stark effect active photonic band gap was investigated. The change of active photonic band gap reflection spectra of the all-optical switch under the pump pulse was simulated; the contrast ratio as a function of control-signal delay and pump pulse intensity, the impact of disorder in the periodicity of the quantum wells and the drift of refractive index on the formation of the resonant photonic band gap were simulated also. Furthermore, due to the fast attenuation the superradiant mode, the sample fully recovers after the passage of the pump pulse for near-resonant pumping, making possible a switch with terahertz bandwidth. The active photonic band gap is very sensitive to the change of the exciton resonant frequency, so the pump pulse energy of the switch is small than that of the normal quantum wells switch.

The theoretical design, fabrication and characterisation of integrated optical phase-modulated Mach-Zehnder Interferometer(MZI) chemical sensing platform are presented. The sensor system, based on silica waveguide materials, is fabricated with ‘silicon microelectronics technology’. The optical waveguides are designed to mono-mode behaviour and high surface sensitivity. These sensor show a effective refractive index detection limit of 10-7. When the sensing waveguide is chemically modified, the sensing platform will show high sensitivity to opto-chemical reaction.. Finally, the refractive index resolution and sensing properties are simulated and analyzed, also, the coming key problems are discussed.

By using similar notation in cylindrical coordinates, the three-dimensional distribution function of focused light field was presented when azimuthally and radially polarized Bessel-Gaussian beam propagated through a high numerical-aperture system with primary spherical aberration. Considering behavior of such beams, the transversal field distributions at focal plane and longitudinal field distributions through focal plane had been simulated at different spherical aberration coefficients. The results show that, in the particular case of a highly focused, azimuthally polarized Bessel-Gaussian beam, the inside radius of annular intensity distribution at the focal plane gradually decreases to a constant with an increase of spherical aberration coefficient, but the outside radius increases. The distance between diffraction focus and Gaussian focus increases more and more, transversal intensity do not take on symmetric distribution about the diffraction focus plane, and the spherical aberration cannot perfectly compensated by defocusing, while the change of light intensity of the radially polarized Bessel-Gaussian beam is similar to that of azimuthally polarized one under different primary spherical aberrations.

When the principal dielectric axes of the anisotropic crystals and the axes built for describing the direction of incident lightwave are different,discussing about the electric field E of the refracted light wave becomes a complex problem. But it is important for some phenomena of nonlinear optics in biaxial crystals. After a plane wave propagating from an isotropic medium into an anisotropic crystal without any restriction on the orientation of the axes above, general expressions about the direction and amplitude of the refracted light wave’s electric field E are given. The result proves that E can be got by solving a quartic equation and using the boundary conditon of electromagnetic field. When the incident light wave takes some special direction or propagate into some symmetrical crystals, the E of the refracted light wave is perpendicular to the direction of the unit wave normal. That is a special case and also be discussed. The results can be used to discuss the distribution of energy between the two refracted light waves.

The squeezing properties of two-mode SU(1,1) coherent states interacting with Bose-Einstein condensate of V-type three-level atoms are investigated with rotating-wave approximation and Bogoliubov approximation by means of quantum theory . The influences of the coupling constant between light field and atoms, the interaction among atoms in Bose-Einstein condenstate (BEC) and the parameter of light on squeezing properties have been discussed. The results show that two quadrature components can be squeezed periodically, the coupling constant between light field and atoms and the interacting among atoms in BEC also shorten the period of the fluctuations of two quadrature components of light and the light parameter has some influence on the depth of squeezing but has no influence on its period.

The 2D imaging in both the azimuth and the range directions of a 2D target is realized in our laboratory-scale synthetic aperture imaging ladar setup. It was reached that the scan strip of ≤10 mm and the resolution of about 1.2 mm×2 mm.

Linear chirp laser signal is often employed as the transmitted signal of synthetic aperture laser (SAL) radar. However, actual frequency sweep properties of fiber laser always produces nonlinear terms such as quadratic and higher order terms. Existence of nonlinear terms produces phase errors during pulse time, leading to blurring of target in range direction and further reduces imaging resolution of range direction. It makes compensation of the nonlinear chirp from laser source. An algorithm of matched filtering in frequency spectrum to overcome the phase error from nonlinear chirp is developed. The results of simulation show that the image in range direction can be well compressed. At the same time, effects of signal compression in the range direction under different parameter situations, such as reference channel length as well as ratio of nonlinear contribution, are analyzed.

Effects of liquid viscosity coefficient on acoustic properties of acoustic low-pass filtering fiber-optic hydrophone are studied theoretically and experimentally. For better descriptions, the key parameter of machanical acoustic resistance which is used to describe the mechanical loss of the system, is introduced into the previous lumped parameters model. Then the improved expression of the transfer function is obtained by the circuit analysis method. Simulation results show that the liquid viscosity coefficient mainly affects the response near the resonant frequency. The resonant frequency is approximately identical and the transfer function amplitude at the resonant frequency decreases sharply, with the increasing of the liquid viscosity coefficient. Acoustic sensitivity frequency responses of different temperature are measured in the standing-wave tube filled with castor oil. The experimental results are in well agreement with the simulation results.

1064 nm, 532 nm frequency-doubled antireflection coating was fabricated by using electron-beam evaporation on LiB3O5 （LBO）. The optical property, adhesion and laser-induced damage threshold were determined by Lambda 900 spectrometer, MTS Nano Indenter and Q-switched pulse laser, respectively. The results showed that 1064 nm, 532 nm frequency-doubled antireflection coating with good performances are obtained by improving deposition parameters. The reflectance of the coating at wavelength of 1064 nm and 532 nm are 0.07% and 0.16%. The critical adhesion and the laser-induced damage threshold are 137.4 mN and 15.14 J/cm2. It is found that the damage of the coating locates in the layer of Al2O3.

A super broadband antireflection coating used in wavelength region of 400～900 nm is designed, which shows an average reflectance 0.2% at wavelength region 410～850 nm and 0.24% at 400～900 nm. The starting design for the computer optimization is discussed. The effect of bandwidth, the difference between high and low index, out-layer index and total thickness on predicting achievable performance is analyzed. For certain bandwidth, increasing difference between high and low index and selecting out-layer material with low index are very important for achieving an excellent anti-reflectance performance. An eight-layer super broadband antireflection coating with high and low index materials of TiO2/MgF2 on the substrate K9 has been prepared. The experimental result shows that the residual average reflectance of 0.44% in the bandwidth of 520 nm can be achieved. It is proved that the design of super broadband antireflection coating with two coating materials is successful comparing with more materials used for the situation of vertical incidence.