The farfield beam patterns after the magnetic fluid sample are simulated. The scheme for realizing the thresholdtunable optical limiters is proposed. The relationship between the output power and the incident power at several different aperture radiuses and different distances between the aperture and the sample are investigated through theoretical calculations. The results show that the threshold value of the optical limiting system shifts to high power when the aperture radiuses are increased and the distances between the aperture and the sample are decreased. The linear relationship between the threshold value and the aperture radius is obtained. The threshold value of the optical limiting system decreases with the increase of the absolute value of the magnetic fluid characteristic parameter (f). The results presented in this work may be helpful for designing the magneticfluidbased thresholdtunable optical limiters.

The principle of optical dualbalanced coherent receive is deduced using Jones matrix, the IQ signal is obtained that contains all the optical information,and the signal processing algorithm based on the IQ signal to demodulate optical signal information is given. Based on this principle, a highspeed MEMS scanning laser heterodyne interferometer is designed, and the thickness map of the test glass is obtained. The interferometer wavefront phase extraction accuracy achieves 0.01 radians, the measurement speed reaches 40 frame/s, and the maximum measured diameter can reach 300 mm, which show the broad application value in realtime optical detection.

An intracavity frequencytripling of a diodeedgepumped passively Qswitched 1 064 nm Nd∶YAG laser is presented to generate high power 355 nm UV laser. Several essential technologies are put forward to achieve the best beam quality such as a volume grating to maintain quasi phase matching with narrow linewidth, optimization and thermal effects compensation for cavity. The task first takes advantage of volume grating and two CBO crystals as SHG and THG nonlinear optical conversion material to obtain high UV laser power output more than 4 W, light quality factor M2<2.5, meanwhile it is the first time to realize thermal effect using 45° Faraday rotator. The achievement is expected to be the popular light source system in lithography instead of conventional excimer laser.

Based on systems of semiconductor lasers with two mutual timedelayed couplings and three mutual timedelayed couplings, the influence of coupling delays and coupling strength to isochronal chaos synchronization was numerically studied. A thought that one coupling delay could be seen as feedback delays was presented in the system with two mutual timedelayed couplings. The condition and law for isochronal chaos synchronization was revealed in the system of semiconductor lasers with multiple mutual timedelayed couplings. The results show that the ratio 2 of two coupling delays is a basic condition to achieve isochronal chaos synchronization with high quality. Increasing coupling strength can improve the quality of isochronal chaos synchronization, and when the coupling strength is lower, the system with two mutual timedelayed couplings is much easier to achieve good isochronal chaos synchronization than system with three mutual timedelayed couplings.

Tm3+ single doped and Tm3+/Yb3+ codoped tellurite glasses with the composition of TeO2ZnONa2O were prepared by meltquenching method. The intensity parameters Ωt(t=2, 4, 6), spontaneous radiative transition rates A, fluorescence branching ratios β and radiative lifetimes τrad of Tm3+ were calculated based on the JuddOfelt theory, and the upconversion luminescence of Tm3+ for glass sample with different Yb3+ doping concentration was measured. The results show that the glass sample can emit strong nearinfrared upconversion emission under the excitation of 980nm pump light. The analysis of Tm3+ upconversion emission process reveals that the intense nearinfrared upconversion luminescence of Tm3+ ions is mainly ascribed to the result of energy transfers: first the resonant energy transfer from Yb3+ to Yb3+ ions, and then followed by one and two phononassisted nonresonant energy transfer from Yb3+ to Tm3+ ions. The energy transfer coefficient and phonon contribution for the above energy transfer process were calculated. Furthermore, the 1.8μm band absorption, emission crosssections and gain coefficient of Tm3+∶3F4→3H6 transitions were calculated and analyzed. The research indicates that Yb3+/Tm3+ codoped TeO2ZnONa2O glass is a promising host material applied for nearinfrared band solid laser.

Nanostructured WO3 mixed with chloroplatinic acid was prepared by solgel method. Fiber Bragg grating was coated with the hybrid material. The asprepared powder was mixed with different ratio of chloroplatinic acid and annealed at different temperatures and their structures were characterized by Xray diffraction. The results show that the crystallinity of WO3 increases with the decrease of chloroplatinic acid and the increase of thermal treating temperature. The experiment demonstrates that after being annealed under 30℃ with the Pt∶W ratio of 1∶9, the sensor has good repeatability, can reach the response speed of 15 s to 4% Hz, and has 140 pm central wavelength change. The sensor shows no sensibility with further increase of temperature up to 500℃.

Environment temperature changes and vibration will cause the random change of phase difference between two arms in the MachZehnder interferometer (MZI), resulting in the instability of interferometer outputs. In this paper, the effect of temperature and vibration on the 3×3 couplerbased interferometer was studied in detail under natural conditions. Results show that the interference frequency caused by temperature and vibration is mainly concentrated in the low frequency section below 100 Hz. In order to eliminate these disturbances, a singlearm compensation feedback loop was designed to stabilize the output signal, and a dynamic compensation method was proposed based on quadrant judgment for distinguishment of positive and negative feedback. In the experiments, two of the three outputs of the 3×3 coupler are transformed from optical single to electrical one, and drives the piezoelectric ceramic to stretch the fiber wound on it after differential amplifier and other feedback circuits, which dynamicly compensate the phase difference drift of the interferometer and stablize the output namely the third output of the 3×3 coupler. Considering the disturbances caused by the temperature and vibration under nature environment, a stable dynamic compensation device was successfully demonstrated which can effectively suppress lowfrequency interference below 160 Hz, and compensate realtime the phase difference drift between two arms of the interferometer, while the output becomes stable with fluctuations less than 5.64%.

The UV atmospheric transmission theory and the nonline of sight single scattering channel model were introduced. According to the model, the transmission loss caused by atmospheric channel under different structure design was quantitatively analyzed. Attenuation was quantitatively simulated under different atmospheres, communication patterns and structure parameters. Experimental results show that attenuation increases with increasing transmission distance; under different visibility, attenuation increasing different, and the higher visibility, the less attenuation, the far transmission distance; transmission distance increases with decreasing launching elevation and receiving elevation, and influence degree of launching elevation is more series than receiving elevation; transmission distance increases with increasing beam divergence angle and decreasing field angle, and influence degree of field angle is more series than beam divergence angle.

A telescope fiber coupling system using aspheric lens for coupling freespace optical field into singlemode fiber in allfiber lidar is devised. Its layout is designed and optimized for coupling efficiency into singlemode fiber through ZEMAX software. Moreover, the preliminary experiments are carried out using the LED and laser as optical source, and then the coupling efficiencies of directive coupling and aspheric lens coupling are compared. Experimental results show that the coupling efficiency using aspheric lens for multimode optical source may be increased by 47% than that of directive coupling, which is close to simulating result of 45%, and that the ratio of coupling optical power for different fibers is roughly close to the square of the corediameter ratio. Furthermore, it is shown that the coupling efficiency of this way for singlemode optical source may be raised by 20%, and that the ratio of coupling optical power is approximately 2.4 times more than the square of its corediameter ratio, which is significant to establish the allfiber rotational Raman lidar.

In order to calibrate the sensitivity of fiber grating hydrophone, a calibration technique of fiber grating hydrophone was studied. In this paper, the working principle of fiber grating hydrophone was introduced firstly. Secondly, using tunable laser and intensity modulation method with workpoint controlling, the signal demodulation and stably measurement of fiber grating hydrophone was realized. Based on these methods, a calibration system of fiber grating hydrophone was established using comparison methods, and its calibration frequency range was 20 Hz to 10 kHz. Finally, using this calibration system, the sensitivity of a fiber grating hydrophone made of equivalent phase shift fiber Bragg grating was calibrated in the frequency range 20 Hz to 10 kHz, and measurement uncertainty of the system was estimated. The results proved that this system can correctly calibrate the sensitivity of fiber grating hydrophone, with its expand uncertainty (at k=2) of 0.9 dB.

An improved block density fast algorithm for steadying shaking image was presented. The jitter of camera system was measured by gyro, while the local motion vectors was estimated by the small area fast blockmatching algorithm, and the global motion vector was calculated by least square method. Small area fast blockmatching algorithm, which has high calculating precision, is good at calculating the local motion vectors. So the least square method can exactly calculate global motion vector by using parts of the local motion vectors. For this reason, the black density can be improved to speed up the algorithm and retain the precision of the global motion vector at the same time. The small area fast blockmatching algorithm was optimized by analyzing the block gridding, and then the fast sensor electronic stabilization algorithm was designed. The simulation and experiment show that the algorithm is slightly more accurate and about 89% faster than the small area fast algorithm.

The dynamic performance of a PZT driver which contains an operational amplifier was studied according to the specific requirements of the image quality compensator in a lithographic objective. Firstly, the impact of the inherent frequency characteristics of the operational amplifier on dynamic performance was analyzed and the parameters of the compensatory network were fixed. Secondly, the impact of the capacitive load of the driver system on dynamic performance was analyzed and the corresponding solution was provided. Finally, the impact of the parasitic capacitance in the driver system was discussed. As calculated, after compensated the PZT driver system had a phase margin of 79 degrees and a setting time of 5 microseconds, and presented no overshoot in step response. The driver would fulfill the dynamic requirements of strong stability, rapid response and little overshoot when the PZT was used as actuator of the image quality compensator in a lithographic objective.

Optical properties of trap pit morphology of multicrystalline silicon (weaklyetched, normaletched and heavyetched) were simulated by solving the Maxwell and material equations, using RF MODULE of COMSOL Multiphysics version 3.5a. The varying laws of surface electric field a component, surface magnetic field y component and reflectivity of three kinds of trap pits were obtained. It is indicated that the value of surface electric field z component and surface magnetic field y component of weaklyetched trap pit is the least, and its reflectivity is the highest(about 35%)at wavelengh of 600nm; followed by that of normaletched trap pit, its reflectivity is about 17%; the value of surface electric field z component and surface magnetic field y component of heavyetched trap pit is the most, its reflectivity is the lowest(about 10%). Compared the experimental date with the simulation results, change trend of numerical simulation results are accorded with that of experimental ones, which provided for the practice production of acidic texturing of multicrystalline silicon as theory bases.

According to the differences between the white LED spectrum and the visible light spectrum, the feasibility of using optical coating to improve the spectrum is discussed. Meanwhile, a novel method is proposed to eliminate blue band of the white LED spectrum. The transmittance of the required optical coating is calculated, and the feasibility of method is analyzed. According to the spectrum of the single LED is different at the different temperatures, the transmittance of the required optical coating is calculated based on the spectrum of the single LED at the temperature 4.9°, 24°, 49°, and the feasibility of using optical coating to improve the temperature stability of the single LED spectrum is analyzed. The results show that the method of using optical film coated on the LED chip does not improve the structure of the white LED to make it similar with the visible light spectrum. The blue band of the white LED spectrum can be eliminated and improve the comfort of the spectrum using the designed optical thin film. The center wavelength and the relative luminous of the analyzed single LED can be stabilized at the 700 nm and 0.2 at the temperature 4.9°, 24°, 49° using the designed optical film. The similarity of the spectrum at the different temperature is improved greatly. The results contribute to the further application of LEDs.

SnO2/Ag/SnO2 trilayer thin films were prepared on glass substrates by RF magnetron sputtering of SnO2 with different O2/Ar ratio and DC magnetron sputtering of Ag. Several analytical tools such as Hall measurements, fourpoint probe and ultravioletvisiblenear infrared (UVVisNIR) spectrophotometer were used to explore the causes of the changes in electrical and optical properties. When O2/Ar ratio is 1∶14, the film had a figure of merit of 1.69×10－2 Ω－1, the resistivity is 9.8×10－5 Ω·cm, and the sheet resistance is 9.68Ω/sq, while the average transmittance is still as high as 85% in the visible light region. In addition, when O2/Ar ratio is 1: 14, The flexible SnO2/Ag/SnO2 trilayer thin films with excellent photoelectric performance can be obtained by magnetron sputtering on PET substrates, the average transmittance is above 85%, the resistivity is 1.22×10－4 Ω·cm, and the sheet resistance is 12.05 Ω/sq.

Xray crystal characteristic parameters are the bases of identification of Xray crystal species and class, kinds of Xray crystal spectrometer fabrication, Xray lines intensity quantitative measurement and Xray monochromatic image diagnosis. On the automatic Xray diffractometer (XRD), based on stability and precision control of θ and 2θ goniometer, special plane crystal holder was made. Bremsstrahlung and CuKα line were attenuated for 5 orders by 40 μmthick Nickel filter, Xray sources was to be CuKα monochromatic source, and transmission power of filter was the criterion of CuKα monochromatic source. For Xray Pentaerythritol(002) plane crystal of Crystal lattice (2d) and integral reflective coefficient (Rc) of CuKα energy were calibrated, there are 2d=(0.87 425±0.00 042)nm, Rc=(1.759±0.024)×10－4 Rad respectively. This kind of experimental method is efficient and convenient on XRD in common laboratory. On XRD, other monochromatic Xray sources can be obtained by changing the material of Xray tube, and integral reflective coefficient of different energy will be obtained by the same way.

A new method to measure the three dimensional (3D) shape is proposed. In the measurement, the elliptic fringe pattern was projected to the surface of the object and the 3D shape of the object can be reconstructed by this method based on phase measurement profilometry. Some calculation formulas for phase and height are derived. A result of our method is compared with that of the phase measurement profilometry (PMP), which shows that the measurement accuracy of this method can meet accuracy requirement of the measurement. Moreover, this method owns strong ability of antinoise. With large noise, this method also can reconstruct the 3D shape of object. Computer simulation and preliminary validate the feasibility of this method.

The squeezing effect and atomic population of the binomial field interacting with a cascade three level atom are calculated accurately without rotatingwave approximation(without RWA) by using the complete quantum theory. The influences of the binomial state field parameter η on the field squeezing effect and the maximum photon number M of the binomial state field on the atomic population are considered. The results obtained from using the numerical method show that with increase of the binomial state field parameter η, the duration of the squeezing effect increases at first and then decreases. The little indentation oscillation appears in the evolution curves of the field squeezing effect, which is caused by virtual photon without RWA. The period of the revivalcollapse increases with the increase of the maximum photon number M, and the atomic population can not collapse completely in the collapse regime, but displays little indentation oscillation. In addition the influence of the withoutRWA terms on the quantum properties of the system are discussed.

Two coupled cavities each containing one twolevel atom are considered, which interacts with cavity via a twophoton hopping. The evolution of the state vector of the system is given when the total excitation number equals two. The squeezing of field is investigated. By means of the numerical calculations, the influences of cavitycavity coupling constant and atomcavity coupling constant on the antibunching effect of field are discussed. The obtained results show that the field does not display squeezing, and the antibunching effect of field has a nonlinear relation with cavitycavity coupling constant or atomcavity coupling constant.

Quantum satellite communication can meet the requirement of quantum mobile communication among sailing, aviation field with longdistance and extensiveness communications, and onboard switching is one of the key techniques in quantum satellite communication. Based on the onboard switching technique in low earth orbit (LEO) quantum satellite communication, a novel algorithm is proposed that is terminal measuredistance method. By using this algorithm, the distances between terminals and its adjacent cell center are measured, and then the distances data are uploaded to the current satellite system, finnaly the satellite system compares the distances and determines whether to handover or not. Mathematical analysis and simulation results show that the proposed algorithm has high reliability, is easy to operate, and can smoothly switch between the different satellites.

The false alarm probability of eavesdropping checks on both AliceBob quantum channel and AliceCharlie quantum channel in the controllable quantum secret sharing protocol using GreenbergerHorneZeilinger states proposed by Y. Sun et al. is analyzed. The reason why the total false alarm probability of eavesdropping checks in the controllable quantum secret sharing protocol using GreenbergerHorneZeilinger states is not equal to 0 lies in the randomness of measurement basis selection for eavesdropping checks. Afterward, an improved controllable quantum secret sharing protocol using GreenbergerHorneZeilinger states is proposed, based on using deterministic measurement basis for eavesdropping checks. Theoretical analysis shows that compared with the original one, the improved scheme can discover the eavesdropping from any internal dishonest participant with twice probability, and possesses much higher security. Moreover, the total false alarm probability of eavesdropping checks in the improved scheme is equal to 0.

Curvelet transform, as a method of multiscale geometric analysis, is more suitable for image processing than wavelet, and more appropriate for analyzing the image edge characteristics of curve and line, which has better approximation precision and sparsity description. In this paper, the methods of integrating SAR image and MS image are proposed based on curvelet transform. SAR image and I image, which is given by a linear HSI transform are given by curvelet transform to obtain coarse coefficients and detail coefficients. The new coarse coefficients are obtained by using edge information and features of SAR image. The detail coefficients are dealt with traditional method that gets max of detail coefficients both I and SAR image.Then, the inverse curvelet transform gets the new intensity I image. Finally degree of distortion and space frequency are used to evaluate the result. The results of experiment indicate that the method excels those of based on HSI or curvelet transform in preserving spectral information and enhancing resolution.

With multiplicative noise present, SAR image segmentation becomes difficult to implement.In this paper, a new energy functional model in introduced which is based on nonconvex regularization. This new model combines the regions as well as boundary properties, which can improve the accuracy of segmentation, and protect the geometric edges of the SAR images as far as possible. Segmentation of regions of interest is performed by numerical solution of the partial differential equations that are derived through minimizing the energy formulation. Experiments on both synthetic and real SAR images demonstrate the effectiveness of the proposed algorithm.

In electronic speckle pattern interferometry (ESPI), the true phase is generally extracted by the phasestepping method, which can only get the wrapped phase. Before the phase can be used to provide quantitative information, the wrapped phase must be unwrapped. But ESPI fringe patterns are contaminated with high levels of speckle noise, the task of phase unwrapping remains a challenge. In this article, a novel phase unwrapping algorithm based on graphcuts is proposed, which treats the phase unwrapping problem as integer optimizations. By the method of energy minimization, the novel algorithm can accurately extract the phase from wrapped phase images containing large amount of noise without prefiltering. For the same simulated wrapped speckle phase map,the RMSE(root mean squared error) of the traditional MaskCuts and LeastSquare are respectively 11.707 6 and 4.977 5, while the new algorithm's RMSE is 0.9459.Numerical simulation and experimental results both verify the excellent antinoise performance of the new algorithm.