The on and off wavelengths are obtained by stimulating the Raman tube filled with different gases in AML-2 air-monitoring lidar. According to the characteristic of lidar light transfer path, a new design about light which introduces the idea of beam-splitting based on polarization modulation is presented to improve the real-time performance. Feasibility of the new method is demonstrated and energy loss is evaluated. The simulated results show that the improved system increases the service life of intruments and the real-time performance of lidar. It provide a choice to improve real-time performance of differential absorption air pollution monitoring lidar in practice.

Based on Brillouin scattering frequency-shift model of laser transmitting through medium and relative atmospheric data, an atmospheric detection model based on detecting Brillouin scattering signal is established. In this model, Brillouin frequency shift is only correlative to the atmospheric altitude. The continuous distribution state of Brillouin frequency shift of low atmosphere is described in detail. The result shows that atmospheric Brillouin frequency shift is distributed from 1.0～1.3 GHz at the altitude from 0～86 km. This model, presents the data agreeing well with practical data and has good continuity and generality.

The effect of outer scale of atomospheric turbulence on tracking precision of tilted tracking system is studied by considering G-tilt power spectrum and the residual variance of tilted tracking system. The G-tilt power spectrum and the residual variance of tilted tracking as functions of the outer scale of turbulence are deduced theoretically. The numerical results show that outer scale of turbulence has great effect on G-tilt power spectrum and residual variance of tilted tracking at low frequency but almost has no effect on the high frequency.

Analytic expression for the reflection peak wavelengths (RPWs) of sampled fiber Bragg grating (SFBG) without chirp is derived and confirmed. Firstly, the refractive-index modulation depth, corresponding to center wavelength, of seeding grating and Fourier series of sampled fiber Bragg grating's refractive-index modulation are obtained. Then the refractive-index modulation depth and local grating periods of sampled fiber Bragg grating are derived. Aided with them, the expression for reflection peak wavelengths of sampled fiber Bragg grating is achieved. Since the duty cycle and the sampling period are involved, the expression guarantees the accuracy of calculated reflection peak wavelengths. In the simulations, with different duty cycle or sampling period, there are agreements between the calculated reflection peak wavelengths (or channel spacing) and numerical reflection spectra. Moreover, this expression is not only available for uniform sampled fiber Bragg grating, but also for AC-apodized and AC-DC-apodized sampled fiber Bragg grating.

To solve the coupled wave function of nonlinear recording hologram, the linearization method was advanced, and two modulating models of refractive index were adopted, the convex curve and the concave curve. Taking the reflective phase hologram grating as an example, the spectral properties of the gratings were analyzed, for recording material with refractivity modulated in the convex curve and concave curve, by the coupled-wave theory. There is great influence on the bandwidth of the spectral properties from different modulating models of refractive index, and it affects the secondary peak value, but the primary peak value and position. The results can explain the diversity of spectral property and the experimental bandwidth wider than that calculated.

Propagation characteristics of the Er-doped waveguide amplifier are studied by the variational method. The variational expression of the propagation constant is proposed in the buried ion-exchanged glass optical waveguide. The unknown parameters of the Hermite-Gaussian trial solution for the field profile are determined by using the variational method. The field distributions of different fabricated waveguides are then determined. The propagation constant and the effective refractive index are calculated using the variational expression of the propagation constant and the determined field distributions. The fact that the effective refractive index is slightly larger than the bulk index shows that the waveguides fabricated are weak ones. High electrical intensity and short annealing time are shown to be useful in the fabrication of buried waveguides. The calculation procedure is simple and the results calculated using the variational method agree with those measured in the experiment.

A novel scheme for all-optical clock component enhancement and clock-to-data suppression of 10 Gb/s non-return-to-zero (NRZ) code based on the effect of gain saturation, chirp induced by semiconductor optical amplifier (SOA) and chirped fiber Bragg grating (CFBG) is proposed and demonstrated. The clock enhancement and 12.9 dB clock-to-data enhancement are achieved after semiconductor optical amplifier and chirped fiber Bragg grating. The transmitted clock is recovered based on stimulated Brillouin scattering (SBS) from the enhanced signal. This clock recovery scheme has the advantage of transparence to data rate and modulation format, low clock jitter, and non-influence of pattern dependence.

The side-hole package technology, a novel fiber grating pressure sensitivity enhancing scheme, is presented. The pressure sensitivity is improved several orders using side-hole package technology, which has reduced the dependence of pressure sensitivity on polymer material parameters through changing package structure. The pressure-sensing model of side-hole package is built using the finite element method and the influence of package geometric configuration on pressure sensitivity is analyzed. The experimentally measured results show that the pressure sensitivity of fiber grating with side-hole package is 5251 pm/MPa, which is 1750 times that of without package. The cross-sensing problem is suppressed by three orders and the sensor can satisfy underwater pressure measurement with high accuracy.

Atmospheric scattering degrades the aerial remote sensing images. To improve the quality of the remote sensing image, a correction method of aerial remote sensing images using polarization information is presented. Atmospheric scattering light has distinct polarization characteristic, but the degree of polarization of vertical object radiance is very small. Object radiance is extracted from image information based on the different polarization characteristics between airlight and object radiance. The polarization images can be obtained by airborne muti-band Polarization CCD Camera. Experiment of image correction was carried out with polarized images in 443 nm, and the experimental result shows this method is very effective on correction of aerial remote sensing images.

Three-dimensional structure reconstruction from image sequence is acquiring much attention in photogrammetry and computer vision. A new algorithm based on affine approximation is put forward to resolve the contradiction of accuracy and robustness in conventional algorithms. Firstly, it synthesizes those missing points in image sequence based on tri-linear tensor, and then rebuilds a new measurement matrix without missing elements, which is decomposed by the bilinear affine factorization method to recover the initial data for the three-dimensional structure of objects. Finally, the initial three-dimensional reconstruction is optimized by the “R-T”-model-based bundle adjustment. Synthetic and real image tests show the new method presents more accurate and robust result and it can be applied to aerial surveying and mapping, industry inspection, virtual reality, cartoon making, military reconnaissance, etc..

A new approach of digital watermark based on information optics is presented. The watermark information is hidden in a halftone encoded computer-generated hologram. The watermark is encoded as a phase function of wave front by means of phase retrieval technique while the host information is taken as the amplitude of wavefront. Furthermore, the encoded wavefront is recorded through the computer generated hologram, and followed by a halftone encoding to achieve the watermark embedding process. The watermark can be retrieved by using either optical or digital Fourier transform on halftone images containing the watermarked information. The simulation results are presented and show good agreement with theoretical analysis. It is shown that the proposed watermarking technique is robust to various image processing operations. The binary characteristic of halftone encoded image grants the embedded watermark the ability to resist printing, hardcopy and scanning.

A novel double wave band sensor based on vertically stacked structure is proposed. It provides the possibility to obtain images in visible/near IR spectrum simultaneously. Its basic principle is to use silicon material's differences of penetration depths of electromagnetic waves with different wavelengths, i.e., visible light with short wavelength mainly absorbed at surface while near IR light with longer wavelength mainly absorbed at deeper location. Through extraction of photocarriers at different depths, images corresponding to their spectrums are obtained. The analysis of results from numerical simulation shows that the device with structure parameters of D1=2 μm, D2=18 μm give best visible/near-IR response with peak values at 550 nm and 1000 nm in the imaging wavelength of 400～1200 nm.

The advantages of scannerless lidar and the operating principle of streak tube imaging lidar are introduced; the relationship between range resolution and spatial resolution is expounded. Based on analysis of the key factors that influence the spatial resolution of streak tube imaging lidar, the equation to calculate the overall spatial resolution is founded, and corresponding mathematical analyses are also made to predict the performance, finally, by means of resolution panel, we set up experiment to validate the spatial distinguishing ability of the system and get the raw resolution image and process the image by noise filtering. Through calculation of the contrast transfer function, we get the practical spatial resolution data and make performance analysis by comparing the practical data with theoretical data.

To compensate of the nonlinearity error of heterodyne interferometers in nanometer measurement, a method for reducing the first harmonic nonlinearity is proposed. Based on the total reflection theory, polarization properties of coated corner-cube retroreflector are analyzed. Then, the effect on the first-harmonic nonlinearity by the polarization properties of reflected light of the cube-corner retroreflector and axial rotation in the motion direction of the measurement cube-corner retroreflector is derived. The simulation results show that the first harmonic nonlinearity is reduced by the axial rotation of the cube-corner retroreflector. When the axial rotation angle is 97°, the first harmonic nonlinearity is the smallest, which is about 0.05 times smaller than the original. When the nonorthogonal error of the two linearly polarized beams is 6°, and the axial orientation rotation angle increases from 0° to 97°, the first harmonic nonlinearity is reduced from 5.30 to 0.30 nm.

A novel measurement and digitalization system of surface defects on optical devices——microscopic scattering imaging is put forward based on international ISO10110-7 surface defects standard and inertial cofinement fusion engineering standard. The multi-beam optical fiber cold light source illuminates the detected surface whose view field is about several millimeters in a special angle. The image of bright defects in black background is formed that is suitable for digital image binary processing. The sub-aperture is detected and imaged using the X-Y scanning system. The information of full surface defects is obtained by stitching the sub-aperture images with the template matching principle. A complete digital evaluation software system of large aperture surface imperfections measurement based on morphology is presented. A group of standard reticules are fabricated by binary optics to scale defects. The resolution of the optical system of defects-microscopic scattering imaging is better than sub-micrometer and the view field of a sub-aperture is about 3 mm. An image array of 5×5 sub-aperture is obtained by two-dimensional scanning system. The full image of surface defects is reconstructed, and the quantitive comparison with the standard value is also presented. The experimental results show that the system is valid for measuring defects of precision surfaces.

A new infrared thermal image method to measure the starting duration of YBCO high-temperature super-conductor (HTS) film chemical etching was proposed. The temperature variation of liquid film on YBCO surface was induced by absorption or release of chemical heat during etching of YBCO film, and the start time of reaction can be tested by real-time collection of the infrared thermal image in the course of liquid film temperature variation. Theoretical analysis and experimental results show that linear liquid film with 2 mm width is adtopted to monitor because all the information of temperature and space change is possessed, and the center of liquid film can be set as an observed character point. The more accurate experimental data can be obtained because of the high sensitivity of temperature change of extraordinary thin linear film made by sliding droplet. The influence of film weight on start time can be avoided with upright YBCO film (LaAlO3 substrate). The start time of reaction between YBCO film and H3PO4H2O( volume ratio 1:300)liquid is about 0.3～0.4 s, which is obtained by the grey-scale variation of a certain cross section of linear liquid film.

According to the birefringence dispersion character of a quartz crystal, the theoretical analysis and numerical simulation about the polarization interference spectrum are given,and then a systematic way of measuring the phase retardation and thickness of the quartz wave plate, which is based on the principle of polarization interferometry, is put forward. With the polarization interference spectrum, the phase retardation of quartz wave plates can be determined at a wide spectral range from 200～2000 nm. Through accurate judgment of extreme points of the polarization interference spectrum at long-wave band, the physical thickness of the quartz wave plate can also be achieved exactly. Experimentally, the polarization interference spectrum of a quartz wave plate is measured with Lambda 900 UV/VIS/NIR spectrophotometer. Under the conditian of 0.1 nm wavelength resolution, the thickness accuracy is 0.1 μm. The result of error analysis shows that the relative error can be reduced efficiently by use of spectrometers with higher spectral resolution and longer spectral band to measure and calculate.

A type of current transducer to the optical measurements of high-voltage current using ferrofluid films has been studied. The basic operation principle and design of the novel sensor is based upon the field-dependent transmitivity. When a thin film of ferrofluids is subjected to a magnetic field applied which is perdicular to the plane of film, a portion of magnetic particles is condensed out from the initially monodispersed magnetic fluid and forms magnetic chains, then the optical transmitivity of the ferrofluid changes. The main advantage of this method in comparison with the optical current transformer on Faraday effect and the conventional electromagnetic current transformer avoids problems in the low SNR and the high-voltage isolation. The sensitivity and response time can be tailored during fabrication to suit the application by changing the concentration, liquid carrier or changing the configuration of the transducer cell.

The heating efficiency for a rotational cylinder shell under CW-laser irradiation is studied. An analytical expression for temperature profile, obtained by integral transforms method (ITM), is utilized to analyze the lag-phenomenon of the maximum temperature rise position relative to the laser peak-intensity position on the shell surface. The expressions of the heating efficiency and the lag-angle are obtained. The results show that the heating efficiency and the lagangle are dominated by three dimensionless parameters: DR (the ratio of cylinder shell radius to R laser spot radius r0), DL (the ratio of thermal diffusion length 4ατL to laser facular radius r0), and DM (the product of irradiation time τL and shell rotation frequency fR). If the same maximum temperature rise arrives to arrive at, there exists the nonlinear relation between the required laser irradiation times for a rotational cylinder shell and for a still cylinder shell, and is independent of the laser power, and the laser power determines the required absolute irradiation time.

The lifetime of plasma channel induced by femtosecond laser in air is investigated by adding external high voltage electric field. The lifetime is extended three times when the voltage reaches 350kV/m in our experiment. Theoretical simulation and analysis show that impact ionization is enhanced and attachment effect is reduced in high-voltage electric field. Also, a sharper falloff in dissociative recombination rate will lead to a corresponding marked increase in the lifetime of the plasma channel. Both experimental and theoretical results prove the feasibility of adding external electric field in prolonging the lifetime of plasma channel in air.

A periodically poled KTiOPO4 (PPKTP) for second harmonic generation (SHG) with 9 μm period, 8 mm length, 3 mm width and 1 mm thickness has been successfully fabricated by applying an external electic field of high pulsed voltage. During the program, the real time monitoring measures such as electro-optical effect method, second harmonic generation two-dimensional method were used. 13.5 mW of 532 nm second harmonic generation green light was obtained pumped by 1 W, 1064 nm fundamental wave. The single-pass second harmonic generation conversion efficiency was 1.35% and the normalized conversion efficiency was 1.69% /(W·cm), which was close to the maximal theoretic value.

Since the spin-orbit coupling parameter (ζ0p≈150 cm-1) of ligand O2- is close to that (ζ0d≈248 cm-1) of the central 3d1 ion in Zn(antipyrine)2(NO3)2:VO2+ crystal, the effect of the spin-orbit coupling parameter ζ0p on the electron paramagnetic resonance (EPR) spectra and optical absorption spectra should be taken into account. Therefore, the EPR spectra and optical absorption spectra of VO2+ in Zn(antipyrine)2(NO3)2 single crystal are calculated based on the two-spin-orbit-coupling parameter model and correlative formulae of the crystal-field energy levels. Theoretical results of EPR spectra and optical absorption spectra of Zn(antipyrine)2(NO3)2:VO2+ are in good agreement with experimental findings. According to the present investigation, the value of this tetragonal distortion of the local symmetry along C4 axis is 0.45 nm. The calculated result shows that the large value of κ indicates a large contribution to the hyperfine constant by the unpaired s-electron. The reasonableness of these results is discussed.

Hypocrellin A (HA) has abundant electronic excited-state properties, and is probably used to new-style photosensitizer of photodynamic therapy, laser dye and novel photoelectron material. The transient-grating properties of hypocrellin A in solvent with different polarity and glutinosity and the solvent are studied with transient-grating technology. The ultrafast process of the transient grating results from the decay of transitional state (TS*) produced by hypocrellin A proton transfer. The lifespan of the transitional state (TS*) is 10.5 ps and is independent of polarity and glutinosity of the solvent.

In order to study the methods for measuring the refractive index of a biological cell based on optical tweezers technology, a ray-optics model has been used to predict the relationship between the trap stiffness and the refractive index of an ideal cell as a spherically symmetric Rayleigh sphere (radius a=10 μm, refractive indices n=1.35～1.70) in a single-beam gradient optical trapping (laser wavelength λ=780 nm, power P= 6 mW, beam waist radii ω(0)=0.6 μm, 0.8 μm and 1.0 μm). Numerical simulation shows that the envelope of each curve is a cubic polynomial fitted well with the cell refractive indices. Results indicate that the calibration process for parameters of a cubic polynomial must be performed on four standard particles before the cell refractive index is obtained by measuring its trap stiffness.

The effect of temperature on the optical properties of biological tissue has been studied by using milk as the simulation sample. Optical properties of milk at 1100～1700 nm were measured by using the double integrating sphere technology in the temperature range of 25～40 ℃. Then the rule of change of optical properties with temperature was analyzed. The results show that the effect of temperature on scattering is greater than absorption. Obvious decrease can be observed with increasing temperature in the reduced scattering coefficient, which decreases by 10% at 40 ℃ compared to that at 25 ℃. And the change of absorptivity of milk with increasing temperature is small and complicated. The results were consistent with the reported results on the study of ex vivo tissue. This study provides valuable theoretical reference and practical experiences and leads to investigate the effect of temperature on optical properties of biological tissue.

Theoretical research on the cascaded second-order nonlinearity based on periodically poled lithium niobate waveguide in pulsed pumping is presented. By numerical simulations the propagation figure is obtained and it exhibits the waveform evolution of pump, second harmonic, signal and difference frequency pulse. The analyses demonstrate that harmonic pulse is continually broadened along propagation length because the walk-off occurs among four pluses due to group-velocity-mismatch, and then converted-pulse-waveform distorts with peak offset. The wavelength conversion experiment has been completed in pulsed pumping and converted-pulse-waveform distortion has been demonstrated.

The mapping approach is a kind of classic, efficient and well-developed method to solve nonlinear evolution equations, the remarkable characteristics of which is that we can have infinitely different ansatzs and thus end up with the abundance of solutions. The traditional ways are to map on the basis of travelling wave reduction, i.e., on the basis of ordinary differential equations. Recently, we have successfully extended this method to the mapping on the variable-coefficients non-traveling wave reduction. Using an improved Riccati mapping approach, we obtain new exact solutions for the (1+1)-dimensional related to Schrdinger equation. Based on the derived solutions, the nonpropagating light solitons(temporal light soliton and bight-dark pulse light soliton), propagating light solitons, and the neutralisation phenomena of light-solitons were constructed.

Considering the imaging restorability, Fisher Information (FI) to evaluate similarity of the point spread functions (PSFs) of different object distances is used to optimize the design of phase mask in practical wavefront coding (WFC) system. A doublet-wavefront coding system is designed based on an infinite focused doublet system with f number 3, effective focal length 100 mm. The simulation and experimental results of encoding and decoding point spread functions show that the doublet-wavefront coding system is insensitive to the object distance with the modulation of point spread function. With object distance from 5 mm to infinite. 3 people (5 m, 10 m, 15 m far a way ) are imaged using traditional doublet and doublet-wavefront coding system respectively. The results show that the sharp imaging's object distance of the doublet-wavefront coding system ranges from 5m to infinite, while the doublet system ranges from 10 m to infinite. In this way the field depth is greatly extended.

The coupling equation set, which describes coupling characteristics of a multi-waveguides directional coupler, is transformed into a tridiagonal linear equation set by Laplace transform. And then general solution of this equation group is obtained by use of the chase method. Furthermore, given incidence condition, solution of the coupling equation group can be obtained exactly by inversion of the Laplace transform. Coupling characteristics of a five-waveguides directional coupler are studied in this method under two conditions of that light beam incidence upon one waveguide and five waveguides. And then analytic expressions of solution of the coupling equation group are obtained and variation curves of optical power in each waveguide are given. This method, which can be used to solve coupled-mode equations set of a multi-waveguides directional coupler with both any quantity of waveguides and any incidence condition, is significant for structure design of a multi-waveguides directional coupler.

When ac voltage is applied, the refractive indexes of liquid crystal droplets and polymer binders match gradually, and the phase-type electrical-controlled switchable focus lens based on polymer dispersed liquid crystal (PDLC) material is switched on and off . In experiments, recipes and characteristics of micrometer size and nano-scale size polymer dispersed liquid crystal materials have been researched. The newly developed optimized nano-scale liquid crystal droplets polymer dispersed liquid crystal recipe is adopted to fabricate polymer dispersed liquid crystal cell samples with thickness of 5～6 μm. And in plane wave and spherical wave interference optical recording system, primary off-axis polymer dispersed liquid crystal focus-switchable holographic lens sample is developed with focal length of 20 mm. Amplified images with positive one-order diffraction are achieved and the driving voltage threshold for “0”, “1” transfer is about 60 V ac voltage. Furthermore, the conception of electrical-controlled focus-switchable optical image system based on polymer dispersed liquid crystal focus-switchable lens integration is put forward.

The optics principle and functions of fused polarization-maintaining fiber coupler is determined by propagation properties. In order to investigate the effects of parameters, based on the theory of thermal-structural-electromagnetic multiphysics field interaction, the biconical models of the fused PANDA fiber coupler were given. Using finite element method the effects of the propagation properties for fused PANDA fiber coupler is analyzed. The results show that longitudinal electromagnetic field distribution is influenced by the refractive index difference between the stress applying part (SAP) and cladding, the distortion of distribution is increase with the D-valve. The propagation constants for HEx11 and HEy11 modes are insensitive to the angle disparity of the birefringent axes, and they affect to the extinction ratio directly by coupling coefficient. The propagation constants for HEx11 mode is sensitive to the ellipticity of fused taper section, the change of Δβx11 is 0.14% when the ellipticity fusion is increased 6.67%, and the numerical results show that it can get high performance when the ellipticity of fused taper section is 0.56.

From the propagation theory of partially coherent light, spectral anomalies and spectral switches of Gaussian Schell-model beams focused by an astigmatic aperture lens are studied. It is shown that, in the case of the astigmatism of the lens, spectral anomalies and spectral switches may also take place on axial points of the focused field. Spectral anomalies and spectral switches depend on spatial coherence, truncation parameter, Fresnel number and bandwidth of the source, but the astigmatism of the lens also affects them. Numerical calculation results are given to illustrate how the astigmatism of the lens affects the spectral shifts and switches. Compared with the astigmatism-free case, the astigmatism can change the critical position where the spectral switch takes place. And the shifts of critical position of the spectral switch take place remarkably to the geometrical focal plane when the astigmatic parameter is large enough. In particular, the spectral switch vanishes as the astigmatic parameter is larger than a certain value.

Considering two-mode entangled coherent light fields, one mode of the fields is poured into the cavity and interacts with a two-level atom. During the course of cavity-QED evolution of the total system, we have a selective measurement to the atom. Through manipulating the evolution time and the parameter of the coherent field which interacts with atom, we can control the quantum statistical property of the light fields outside of the cavity. In certain conditions, the non-classical light such as anti-bunching and squeezing state can be generated, also we can change the strength of anti-bunching and squeezing of the light fields without interaction through controlling and tunneling the parameters. In this way, by using the simple resonance interaction between cavity and atom and the entangled correlation between the coherent light fields, we have implemented the target, that is, control or change the non-classical properties of coherent light field remotely without indirect measurement.

The two kinds of 3ω harmonic separator were prepared by electron beam evaporation with different materials. Laser induced damage threshold (LIDT) was measured at 1064 nm and the damage morphologies were mapped by Alpha-Step 500 meter. It was found that there are two different damage geometries: shallow denudation and deep crater. Shallow denudation in a certain range had same depth at different energy fluences, and material was removed from the top film layers. Deep crater had different depths caused by the combination of melting vaporization and fracture of inner defects of coatings, which was the main cause for decreased damage threshold.

In order to realize accurate colorimetric characterization for a scanner, several polynomial regression models with different number of items and different conversion types were evaluated. The items of polynomial included 3, 5, 9, 11, 18 and 20, and the conversion types consisted of manifold transformation from scanner RGB space to standard CIEXYZ or CIELAB colorimetric space。An identical scanner was colorimetrically characterized with these polynomial models utilizing ANSI IT8.7/2 as color targets. Experimental results showed that the performance of these models were quite different and the linearization of scanner RGB signals improved the model accuracy when the items of polynomial were less than 11, while the differences disappeared and the linearization decreased the model accuracy along with the items more than 11. In this experiment, the polynomial conversion from raw scanner RGB to CIEXYZ with 20 items gave the best performance with the mean/maxmium color defferences of 0.832/2.988 CIELAB units.

In order to research the human color vision characteristics, the color discrimination threshold experiment at the five basic CIE color centers was carried out by a panel of 3 observers with normal color vision on the CIE1976 a*-b* plane using CRT-generated color stimuli based on the psychophysical method of interleaved staircase. The observer test accuracy was estimated using performance factor PF/3, and the color discrimination thresholds were represented via chromaticity ellipses. The detailed processing and analysis of the experimental results indicated that the color discrimination characteristics of human eyes were different for individual color regions and color directions in the iso-lightness a*-b* plane, and namely the CIE1976 a*-b* plane is visually non-uniform. The visual color-difference scale in the red-green direction was generally smaller than that in the yellow-blue one for the five CIE color centers. The experimental data could provide references for the improvement of uniform color space and color-difference formula.