A new spectrometry is developed to obtain near-ground the optical parameters of atmospheric particles. The Active Differential Optical Absorption Spectroscopy (DOAS) system is developed to measure the optical parameters of atmospheric particles. Under the clean atmospheric condition, the reference optical path is designed to calibrate the system.The broad wavelength band xenon arc lamp is used to monitor the optical parameters of atmospheric particles as light source of differential optical absorption spectroscopy system. The model of optical depth is studied to retrieve the optical properties of atmospheric particles. The optical depth of atmospheric particeles, Angstrom turbidity coefficent, Angstrom wavelength exponent, and visibility were retrieved during the field campaign. Angstrom parameters were retrieved by log-linear regression. The total atmospheric absorption are measured to attain average regional concentrations basing on the active differential optical absorption spectroscopy system, which is more representative and applicable.

A wireless optical link in length of 610 m is established in Lanzhou area to investigate the light intensity distribution and fluctuation characteristics of Gaussian laser under different weather conditions. The three-dimensional pseudo-color transform method is utilized to analyze the spatial distribution of light intensity. The results show that the intensity distribution of the main lobe within the light spot follows the Gaussian distribution. The steepness of light intensity distribution decreases and the attenuation of light intensity increases according to the order of sunny day, cloudy day and overcast day in turn. Moreover, the atmospheric scintillation index is analyzed by using the measured light intensity data. The results show scintillation index of sunny day, sunny day after rain and overcast day are 0.225 4, 0.189 2 and 0.188 8, respectively. This indicates that the light intensity fluctuation in sunny day is higher than sunny day after rain and overcast day. The probability density distribution of light intensity is obtained by using nonlinear fitting of histograms of the normalized optical intensity data. They all conform to log-normal distribution. Especially, the probability density in sunny day is more consistent with log-normal distribution, the goodness of its fitted curve is up to 0.997 50.

Wide band solar irradiance spectrometer that the wavelength coverage is from 400 nm to 2 500 nm uses fèry prism to disperse composite light, with linear array CCD controlling scan of spectrum. To achieve the high-precision spectral calibration of the instrument, asingle-wavelength laser and an OPO laser are used as light sources in the laboratory. Through thespectral scanning, the correspondence between the calibration wavelength and the CCD pixel is obtained.According to the prism and optical design parameters, the spectral calibration equations that achieve full-band spectral calibration are derived. It is verified that the spectral calibration uncertainty is better than 0.5 nm by comparing with other characteristic wavelengths. Comparing measured results with the simulation of atmospheric radiation transmission software that is named as modtran4, the measured atmospheric absorption peaks are in agreement with the simulation results. The results of calibration in the infrared wavelength region are compared with the traditional polynomial fitting method, which shows that the calibration results aresuperior to the traditional polynomial fitting method. It is proved that the calibration method is correct and the instrument design is rational.

Based on circuit analysis, this paper shows that the number of peak points can be determined by short-circuit currents and maximum-power point currents of all the arrays in series. The principle is established based on which the number of the peak points is to be determined. Furthermore, based on the dynamic characteristic of solar array, this paper establishes the rule for determination of the relative position of the global maximum power point. In order to track the global maximum power point within an appropriate period, a reliable technique and the corresponding computer algorithm are developed for global maximum power point tracking control. It exploits a definable nonlinear relation is found between variable environmental parameters and the output current of solar arrays at every maximum power point, obtained based on the dynamic performance corresponding to partial shading conditon.

The Lumogen as a low-cost organic material is deposited on the surface of the CMOS imaging sensor using a vacuum thermal evaporation system. The constant dark current noise of the CMOS is shown that no damage to the CMOS is caused in the process of the depositing film. The photo response nonuniformity is increased while the dynamic range is decreased with the argument of the Lumogen-film thickness. Furthermore, the quantum efficiency is increased firstly and then decreased and reach to the optimum 10% when the thickness of the Lumogen film is 389 nm. Meanwhile, the photo response nonuniformity and dynamic range are in a relatively good condition.

Based on the comparation and analysis of phase compensation methods of 90 °space optical hybrid, two new methods were proposed. The first method is that 1/4 wave plate on the local oscillator laser branch is rotated to compensate for the phase difference and the first 1/2 wave plate on the signal laser branch is rotated to adjust the power ratio of I/Q branchs. The second method is that 1/2 wave plate and 1/4 wave plate on the local oscillator laser branch are rotated respectively to the calculated angle to achieve a predetermined phase difference and power ratio. The simulation analysis and system experiment of the two methods were carried out. The results of the first method show that when the angle between 1/4 wave plate fast axis and x axis varies from －10° to 10°, the phase difference ranges from －14° to 29° and power ratio ranges from 0.7 to 1.4; when the angle between 1/2 wave plate fast axis and y axis varies from 35 °to 55°, the power ratio ranges from 0.47 to 2.1. The positions of 1/2 wave plate fast axis and 1/4 wave plate fast axis were solved by the second method when I/Q phase difference is respectively 80°, 85°, 90°, 85° and 100 ° and the I/Q power ratio is 0.5, 0.75, 1, 1.5 and 2. Either of this two methods can set the phase difference and power ratio simply and precisely，which is advantageous to the phase locking of the optical phase-locked loop and the enhancement of the intensity of the demodulated signal.

A method to detect the impact energy using the fiber Bragg grating as the sensing element was presented. A simple impact system was built to detect the incident stress wave energy while fiber Bragg grating were axially symmetrically pasted to the round rod. The experiment result shows that both the amplitude of incident stress wave and energy transfer efficiency reach the biggest with two rod positive impacts. The energy of incident stress wave is mainly concentrated in the range of 0~5 000 Hz based on the analysis of signal in frequency domain. The energy transfer ratio of impact bar to round rod is more than 93% while comparing the incident stress wave energy and the kinetic energy of the impact bar, which meets the basic requirements of the testing for the impact mechanical properties.

To improve the imaging quality of intensity correlation method and avoid the complicated estimation and extra error, the phase retrieval procedure of high-order intensity correlation was ameliorated. Based on the quantitative discussion of the signal to noise ratio of high-order intensity correlation phase measurement, the third-order intensity correlation imaging was selected to simulate the far-field object measurement, according to which the magnifying of spectral modulus error is analyzed.To solve the problem that the spectral modulus would be magnified in the process of phase calculation, the phase closure regularization algorithm of improved phase retrieval was proposed combining phase extimation and phase measurement. Further, the effectiveness of the improved method was verified in the designed indoor experiment by comparison with previous methods of the steepest decent mthod and prior information iteration method. The results show that image error caused by the proposed method is lower than that of the previous methods, which improve the quality effectively.

In order to detect dim infrared targets from a mass of high resolution images in wide field of view system rapidly and accurately, a novel target detection method based on a phased strategy for research and multi-feature fusion is proposed in this paper. First of all, a saliency detection algorithm based on frequency-domain is carried out to extract candidate region which may contain targets. Then, invariant corner detection algorithm is adopted in candidate region to determine the presence of suspicious targets. Finally, the real targets can be confirmed by time-space coherence in multi frames. The experiment proves that the proposed method can detect dim infrared targets with small calculating amount, high detection probability and low false alarm rate. It is suitable for Infrared Search and Track system in practical engineering.

The Sensor Pattern Noise (SPN) is easily contaminated by CFA interpolation noise and JPEG compression noise. These unwanted artifacts may result in false identifications in SPN-based source camera detection. A preprocessing method of SPN based on spatial smoothing was proposed in order to improve the accuracy of source camera detection. It is assumed that the SPN is a random signal similar to white Gaussian noise (WGN), and has a flat frequency spectrum similar to that of WGN in the frequency domain. Based on this assumption, WGN-guided filtering was used in the spatial domain in the proposed method. The spatial smoothing effect can suppress the unwanted artifacts of the SPN. At the same time, the SPN can maintain its own properties and possess similar characteristics with WGN. The proposed method was evaluated on our own database of camera images from cellphones. The experimental results show that the proposed method outperforms the existing preprocessing methods, the accuracy of the source camera detection being increased by more than 0.026 in terms of the Kappa statistical coefficients. The robustness to JPEG compression of the proposed method is also better than others.

Based on digital holographic tomography and transverse interference system, by means of rotating the spun polarization-maintaining optical fiber within 180°viewing angle, optimal digital holograms of a section of spun polarization-maintaining optical fiber were recorded by CCD, and then the phase information was extracted through digital image process and the angular spectrum algorithm. Using the filtered back-projection algorithm, the 2D refractive index distribution of each cross-section was retrieved in order to constitute the 3D refractive index distribution of a section of spun polarization-maintaining optical fiber, which revealed the 3D inner structure of the fiber. The measurement results show that the stress legs rotate synchronously with the spin of polarization-maintaining optical fiber, and the refractive indices of the fiber core, stress legs and cladding are unchanged. Finally, the position of the stress legs was achieved by edge detection algorithm and then the spun angle was computed.

CO and CH4 as the fault gases in transformer, the detection of their concentration has important significant in transformer maintenance. In order to detect CH4 and CO gas concentration in transformer accurately, a photoaoustic spectroscopy multi-component gas detection system based on broadband thermal radiation light source has been developed. Compared to resonant photoacoustic cell based photoacoustic detection system, the non resonant photoacoustic cell used in the system has the advantage of small volume, easy to processed, high sensitivity and the intensity of signal is the same everywhere in non-resonant photoacoustic cell, thus reduce the requirements for the installation of the detector. The performance of the system was evaluated by detection of CH4 and CO. First, the relationship of the intensity of photoacoustic signal in non resonant photoacoustic cell between the radius and the modulation frequency was simulated by theoretical, it is illustrated that the signal enhanced with the reduction of the radius and the modulation frequency. Then the optimum modulation frequency of the system was determined as 22 Hz by the response of the system under different modulation frequencies. The function relations of photoacoustic signal and the temperature were studied, then the photocoustic signal was corrected by temperature compensate based on the function of signal and gas temperature under optimum modulation frequency to eliminate the impaction of temperature to photoacoustic signal, the stability of the system was improved after temperature compensate. The drift of the signal to temperature is 0.023 23V/℃ and 8.383 48×10－5 V/℃ respectively before and after temperature compensate. At last, the system was calibrated by different concentrations of CH4 and CO gas, the experiment show that the photoacoustic signal increased with the increasing of gas concentration and the linearity can reach to 0.995 and 0.998 4 respectively for the detection of different concentrations of CH4 and CO gas. The multi-component gas detection system based on broadband photoacoustic spectroscopy has the sensitivity of 1μL/L for CO and CH4 detection under atmospheric pressure with the 1s integration time. The developed system has low cost, good linearity and the sensitivity conform to the requirement of national standard in the process of transformer maintenance.

A texture reconstruction method based on Markov random fields optimization was proposed to reconstruct the complex free-form shapes. The method used a three-dimensional digital device developed by laboratory to capture the range data and the texture images, and registered the local capture range data into global coordination system to establish the surface of the object. To build a realistic textured model, the captured texture images were mapped to the reconstructed surface by coordinate transformation, and a texture fusion processing was followed. The proposed method does not impose any constraints on the topology of the surface, and a realistic textured model of the free-form surface can be achieved. The data collection and realistic three-dimensional reconstruction of material object were experimented by the proposed method, the results show the reliability and effectiveness of the proposed method.

In order to optimize the fluorescence detection capillary electrophoresis system and improve the detection sensitivity, the signal noise characters were studied when separating 100~1 000 base pair deoxyribonucleic acid ladder under direct current electric field in hydroxyethyl cellulose solutions. The dependence of signal noise on separation electric field intensity, polymer concentration, hydroxyethyl cellulose molecular weight, the effective length and the capillary shape were investigated. Experiment result shows that optimum parameters can be obtained under best signal noise ratio, which are the separation electric field strength of 500~600 V/cm, hydroxyethyl cellulose concentration of 0.6%~0.7%、hydroxyethyl cellulose molecular weight of 250, round inner diameter of 50 μm and effective capillary length of 8 cm.

A laser ranging of dual-sweep frequency scanning interferometry system based on double-sideband modulation was demonstrated. The electro-optic double-sideband modulation was used to create dual swept signals with opposite scanning directions. For each receiving terminal, the beat frequency signal related to relative distance was obtained. By multiplying both beat signals, measurement errors caused by disturbances in the optical path could be greatly reduced. The system was simulated in Optisystem. The simulation results indicate that the variations in the optical path length are eliminated efficiently. In addition, an experimental structure was proposed with vibrations in the optical path length. The experimental results show that the vibrations are suppressed for over 14 dB, which indicates that the precision can be improved effectively.

In this letter a 1 060 mm distributed feedback laser with an optimized double-trench ridge waveguide structure is presented. The lateral mode stability is strongly improved under continuous-wave operating condition. The maximum single spectral and spatial mode output power is approximately 300 mW with a side mode suppression ratio larger than 45 dB. The capability of the device for green light generation is also demonstrated experimentally by pumping a periodically poled lithium niobate waveguide crystal, which the power of the green light is about 3 mW.

The long cavity "8" shaped erbium-doped fiber laser to produce a square wave harmonic mode-locked pulses were studied experimentally. This type has a smooth broadband pulse spectrum shown as a square wave pulse on the oscilloscope, but confirmed that the autocorrelation trace of pulse noise categories, namely noise-square wave pulse. Experiment by adjusting the laser cavity parameters, such as polarization controller and pump power, gets up to 5th order harmonic mode-locked noise-square wave pulse. Experimental results show that the noise-square-wave pulses generated in the fiber laser is not infinitely increasing the pulse energy, but under certain conditions will produce a pulse division, square wave pulse harmonic mode locking phenomenon.

PbSe quantum dot doped bare-optical fibers are prepared in laboratory by drawing sodium-aluminum-borosilicate-silicate-glass fusant and annealing heat treatment. The fibers are in the diameter of 80~130 μm. Transmission-electron microscope measurement shows that the prepared PbSe quantum dot in the fibers are in the diameter of 4.2~5.5 nm and with the doped volume ratio of 1%. The flexibility of Pbse quantum dot doped fibers is tested initially. The photoluminescence spectra of fibers are measured upon 980-nm pump by a fluorescence spectrometer. There is evidence to show that the available annealing condition of PbSe quantum dot fibers is different from PbSe quantum dot doped-bulk glass. When the annealing temperature is within 500~600 ℃ and the annealing time spans 5~10 h, the PbSe quantum dot fiber shows strongest photoluminescence emission, peaking wavelength ranging 1 300~1 450 nm and full width at half maximum coming to 200~330 nm. The optimum annealing temperature and time are 600 ℃ and 7.5 h, respectively. The PbSe quantum dot fibers obtained in this paper can be used to format PbSe-quantum-dot-doped-fiber gain devices based on glass (such as fiber amplifiers and fiber lasers) in the future.

In order to solve the problem that large deviation of the refraction index and temperature coefficient of refraction index obtained by regression calculation from the experimentally measured ones comes out when ZEMAX method is used for solving these empirical formula constants and regression calculation, 1stOpt differential evolution was used to calculate the temperature coefficient of refraction index empirical formula constants. With fluoro-crown D-FK61 and flint H-TF3A optical glass as examples, the λtk coefficients calculated by the proposed method are consistent with the general numerical range of 0.08~0.33, and the difference of refractive index and its temperature coefficient between the value obtained by regression calculation method and the measured value is less than 1×10－5 and 2×10－7/℃, respectively. As an effective supplement of ZEMAX software to calculate the temperature coefficient of refractive index of the optical glasses, the proposed method greatly improves the accuracy and can provide accurate optical parameter guarantee for thermal compensation optical system design.

Large scale tilted-L-shaped chiral nanostructures were fabricated using oblique angle deposition on polystyrene nanosphere templates. SiO2 layer is deposited on the polystyrene nanosphere templates and the Ag layer is deposited on the SiO2 layer to form a metallic arm of tilted-L-shaped chiral nanostructures. Another metallic arm is deposited in the perpendicular direction on the polystyrene nanosphere templates directly. The chirality of tilt-L-shaped chiral nanostructures originated from the different altitude of two metallic arms. By manipulating the thickness of SiO2 layer the circular dicroism can be easily manipulated. Finite element method was used to perform the simulation of tilt-L-shaped chiral nanostructures. Simulation results demonstrate that the circular dicroism mechanism of tilt-L-shaped chiral nanostructures can be explained by chiral plasmonic Born-Kuhn model.

Graphene-based Split Ring Resonator (SRR) metamaterial is proposed with capacity of modulating transmitted THz waves based on the principle of surface-plasmon-polariton.The resonant strengths of plasmonic modes can be significantly enhanced by increasing the Fermi level of graphene, changing the gap distance of SRR or by stacking graphene layers, thus high modulation depth is achieved in both higher frequency region and lower frequency region. Modulation depth of 81% and 68% are achieved in the two regions, which can be further enhanced to 93% and 95%,provides a dynamical modulation based on controllable Fermi level of graphene. This graphene-based design paves the way forthe design of THz applications, such as modulators and absorbers.

To improve the utilization of spectrum resources and solve the problem of large volume of traditional filter, a metamaterial filter with a compact size of 15 mm×20 mm was designed by using the high integration split-ring resonators. Based on time domain finite integral method, the response between the reflection coefficient curve of the split-ring structure filter and the electromagnetic parameters was analyzed. By loading tunable diode into the gap of split-ring, the filter was continuously tunable at X-ray band (from 10.9 GHz to 12 GHz), extending the operating frequency band of the filter. The bandwidth of the designed filter is about 11.0%，return loss minimum is 32 dB and insertion loss maximum is 0.38 dB. The results illustrate that the split-ring metamaterial filter shows the characteristics of compact size, wide bandwidth and good band pass.

The formula of electron energy loss spectroscopy of metal nanostructures was deduced by Green function. Several typical structural systems were simulated by finite difference time-domain method. The regulating effects of the distance between the moving charge and the structure, and the liquid crystal environment on the electron energy loss spectrum were numerical simulated. The simulation results show that the electron energy loss spectral peak decreases when the distance between electron and nanostructure is increased. When the liquid crystal material or isotropic substrate material is added, the peak value of electron energy loss spectrum is redshift，but with the tilt angle of the optical axis changes, the modulation effect is limited. The surface plasmon resonance on metal nanoparticles can be studied by calculating the electron energy loss spectrum, which provides a basis theoretical for the design of highly complex plasmonic nanostructures.

Based on the crystal field theory (CF mechanism) and the charge transfer mechanism (CT mechanism), the spin Hamilonian parameters (EPR parameters), the optical absorption spectrum and the charge transfer transition energy levels of C3H7NO2∶VO2+ crystal are calculated by the double spin orbit coupling parameter model, the high-order perturbation formulas of spin Hamiltonian parameters and the crystal field energy formulas. The results calculated by using the CF mechanism and the results calculated by using the double mechanism are compared. It is found that the contribution of the CT mechanism to the C3H7NO2 crystal doped with high valence vanadium ion (V4+) could not be ignored, when calculating EPR parameters of this crystal.

Effect of temperature and size on the dielectric function of noble metal nanoparticles are analyzed theoretically, and the optical properties of the nano-spheres are calculated including the dispersion relation and temperature characteristics of refractive index. The results show that the real part of dielectric function of the bulk gold material or gold nanoparticles rise with increasing of temperature, but the imaginary part demonstrate different temperature characteristics. For the absorption efficiency of the Au nano-sphere,the peak value of the absorption efficiency increased with the increasing of temperature, and the temperature sensitivity of the absorption efficiency decreases with the particle size increasing at the range of 10~100 nm.

In order to realize the rapid and high precision calibration of standard scattering plate, the standard scattering plate calibration system used in calibration visibility meter was established. The design method of panoramic imaging colorimeter optical system of the calibration system was researched. Based on the optical properties of parabolic reflector, the calculation method of paraboloid surface was deduced. Then, according to the requirement of the calibration system optical system, the design of optical system of panoramic imaging colorimeter optical system was completed. Finally, the panoramic imaging colorimeter optical system was modeling analyzed, and an experiment was designed to verifies the correctness of the design and simulation results. The experiment shows that the spatial measuring range is in the range of incident angle from 0°to 90° and azimuth angle from 0°to 360°; and the angular resolution is 1° which satisfy the design requirements of the optical system of the standard scattering plate calibration system used in a calibration visibility meter.

According to the development needs of in situ monitoring equipment of MOCVD, a multi-functional in situ monitoring probe was designed， which can measure three infrared thermometry with reflectivity correction and reflectivity curve of two different wavelengths, namely: 940 nm/1 550 nm double-wavelength colorimetric thermometry, 940 nm monochromatic radiation thermometry, 1 550 nm monochromatic radiation thermometry, 940 nm reflectivity curve and 1 550 nm reflectivity curve. The test measuring analysis was done for the properties of in-situ monitoring probe, the silicon (111) substrate growing blue light LED epitaxial wafer with InGaN/GaN MQW structure in homemade MOCVD system by using the probe, was monitored on-line. Result shows that the lowest range of three infrared thermometry is equally 435℃; the accuracy within 1℃ colorimetric temperature range from 900℃ to 1 100℃; the repeatability within 0.7℃ from 700℃ to 1 100℃; insentive to changes in height within 2 mm; and the method can avoid the affection of the effective area change of detector aperture. The relative error of n-GaN layer thickness measurement was 3.6% by analyzing 940 nm reflectivity curve. So it can be seen that MOCVD in situ thermometry and film thickness measurement can be achieved by the probe at the same time. The design can provide reference for the developing of MOCVD in situ monitoring device.

Aiming at the defects of the poor uniformity of concentration distribution and the focused spotshape does not match with solar cells in the traditional point focus Fresnel lens, square spot uniformconcentration Fresnel lens was designed by using the method of off-axis non-rotationally Symmetric Superposition. The square non-rotating symmetry structure was adopted in the lens, a square hole was intercepted in the center of the lens when the lens was designed, which can reduce the center peak irradiance of the focal spot and improve the concentrated distribution on the receiving surface in order to improve the uniformity of the spot light.The ray tracing method has been used to simulate and analyze the influence on the condensing performance caused by structure parameter of lens such as off-axis offset,the length of hole and the off-axis focus length . The results show that the shape of the focus spot of the lens designed by this method is square, and the concentration uniformity is up to 90%.

In order to investigate the influence of the optical elements of Czerny-Turner (CT) optical path structure on the optical properties of the spectrometer when the optical elements are deviated from the theoretical design parameters, the mathematical model was established to successfully restore the asymmetric CT optical path structure designed by Zemax, under the condition of unaffecting the spectrometer resolution, the components of adjustable redundancy was got. The results show that the adjustable range of the deflection angle of the collimating mirror and the diffraction grating is ±0.19 and ±0.17 degrees, and the adjustable range of the condenser and the CCD is ±0.12 mm. The adjustable range of the above four variables is the smallest, which has a great influence on the final resolution of the spectrometer. The research provides the references for the mechanical adjustment mechanism of each optical element in CT structure.

In this paper, a three-group inner-focus zoom system using dielectrowetting-based triple liquid lens and conventional fixed lens is proposed. When the first and the third components are fixed, the focal length of the system is changed by moving the intermediate liquid lens group. The self-zooming property of the liquid lens is realized to maintain the image plane. The initial structural parameters of the system is deduced by the optical power Gauss brackets method. The optical system is designed and optimized by Zemax software, and then the image quality of the system is analyzed. Results show that the system can achieve continuous zoom in the range from 2.7 mm to 20.3 mm; the total length of the system is decreased to 22 mm; the zoom ratio reaches 8 and MTF value is more than 0.4 at 180 lp/mm.

An optical alignment method based on color / relative position of guidance light source is designed, landing boat pilot can determine whether is yawing and the degree of yawing through the relative position of the light source with different colors, so as to improve the pricision and safety when entering into well-dock quickly. Guidance light source beam is of 90 ° horizontal and vertical angle of view, and illuminate sea surface farthest to 200m for uniform lighting, with CREE XPE LED, free-form lens is designed by improved grid mapping method to obtain the required rectangular illumination field. The simulation and experimental results show that the designed LED guidance source can meet the illumination requirements of the landing alignment system.

The interaction of light and matter can induce many strange quantum optical phenomena, in which EIT and EIA are the most typical ones. In this paper, a radio-frequency field is introduced between two hyperfine levels of the excited state into a well-studied lambda three level system to form a modified quasi-lambda four level system consisting of an optical-radio two-photon coupling field and a probing field. Both EIT and EIA can be obtained in this system. By discussing the quantum coherence process after the optical-radio field is turned on until the system is stable, the generation and transformation of EIT and EIA during this period of time are analyzed, which is helpful to probe the correlation between two phenomena and to seek the method to regulate and control them.