Based on the Fourier factorization process in Lalanne′s empirical method and Gtz normal vector method,a fast convergence solution was proposed for Fourier modal slice absorption method.The gradient vectors of analytic boundary function were used to simplify the Fourier factorization process in Gtz normal vector method,which made the caclation time for a single wavelength point reduced by 2 orders of magnitude.4 typical types of normal vector fields were built by inverse distance weighting algorithm,and the degrees of freedom in normal vector method was reduced.According to these 4 normal vector fields and the Lalanne′s method,5 types of convergence improved matrice were finally presented.By pre-selection among the 5 matrice,an optimal matix could be implemented in the caculation of Fourier modal slice absorption method to guarantee fast convergence.Calculation results demonstate that for a simple silicone structure the optimal matrix has 2 diffraction oders improved compared with the un-preferred slected matrix,and effectively improves the simulation rate of diffraction.The proposed fast convergence solution is expected to improve the efficiency for grating design and analysis/testing of integrated circuit.

A theoretical model for calculating the diffraction efficiency kinetics of the grating recorded by two parallel circular polarized recording beams was proposed,based on Jones-matrix and photochromic two-state theory.The diffraction efficiency of bacteriorhodopsin grating was measured by system of four-wave coupled light path.The theoreical analysis and the experimental results show that,in the condition of adding linearly polarized auxiliary violet light,when linearly polarized reconstruction light parallel with linearly polarized auxiliary violet light,the diffraction efficiency of bacteriorhodopsin grating is maximum;when linearly polarized reconstruction light perpendicular to linearly polarized auxiliary violet light,the diffraction efficiency of bacteriorhodopsin grating is minimum.The angle between linearly polarized reconstruction light and linearly polarized auxiliary violet light produces a cosine modulation on the kinetics of the diffraction efficiency.It indicates that parallel circular polarization recorded grating in bacteriorhodopsin induced by polarized violet light became polarizing grating.

An ultra-high birefringence photonic crystal fiber was designed,which is composed of an elliptical all-solid hole doped with 80PbO·20Ga2O3 in the core and a cladding with periodic hexagonal-lattice air holes.The performance of the modal birefringence and the contribution of different factors were investigated by the full-vector finite-element-method.Numerical results indicate that the modal birefringence has a magnitude of order of 10-1 in the range of wavelength from 910 nm to 1 931 nm.At the wavelength of 1 550 nm,we acquired an extremely high birefringence of 1.256×10-1 and the small effective areas of both orthogonal polarizations (<0.7 μm2).The design of the fiber will be highly meaningful for the development of interferential fiber optic sensors,nonlinear optic and polarization-preserving devices.

The control target of stray light is deduced based on solar power transmission and the allowable stray light radiance at the exit pupil.Two schemes used to eliminate direct radiation were present,one way is setting primary baffle and secondary baffle,the other way is only setting primary baffle and Lyot stop near the exit pupil.Theoretial analysis indicates that by setting the secondary baffle the first scheme will increase the obscuration ratio,and by setting the Lyot stop near the exit pupil the second one will appear vignetting.Since the requirements of receiving /emission efficiency for optical antenna are very high,it′s also needs to take into account the energy in the design process.The receiving /emission efficiency and stray light suppression level of the two scheme were analyzed to some cassegrain optical antenna.The emission efficiency and stray light suppression level of the second scheme is better than the first,but the receiving efficiency of edge field is slight lower.Finally the second way was used to control the stray light of the optical antenna prototype,and its stray light level was tested.The results show the extinction ratio are lower than -40 dB when the range of off-field angle is from 1° to 20°,it meets the requirement.

In the free space coherent optical communication system of satellite-ground link,atmosphere turbulence and tracking error will affect the mixing efficiency and the bit error rate.According to the mixing efficiency formula,both the relationship between system mixing efficiency and atmosphere turbulence intensity and the relationship between system mixing efficiency and tracking error were derived and simulatied.The results show that the mixing efficiency will decrease with the increasing of tracking error and atmosphere turbulence intensity.When the tracking error is greater than 12 μrad or turbulence intensity exceeds 10-16,the mixing efficiency is close to 0.An optical mixing efficiency model and a bit error rate model were built in atmosphere turbulence with tracking error,and the homodyne efficiency with different conditions was calculated.Atmosphere is the significant factor of mixing efficiency when tracking error is less than 2 μrad.Then,the tracking error will be as the leading factor with it increasing.According to the reference values of traditional coherent communication system,the maximum of mixing efficiency is about 67.8%,and the system receiving sensitivity is 17 photon/bit when the error rate is 10-9.

A kind of Photonic Crystal Fiber based Long Periond Grating (PCF-LPG) was analyzed on basis of the local coupled-mode theory.Transmission spectrum of the coupling between LP01and LP02,LP01and LP11,was numerically modeled after building the collapse model.Compared with transmission spectrum calculated with the coupled mode theory,the local coupled-mode theory was found in a good agreement to analyze the strong PCF-LPGs.The changes of resonant wavelength were discussed in different grating periods,number of periods and the depths of cladding collapse.The results indicate that,with the increase of grating period,the resonance wavelength shifts to shorter wavelength;with the increase of number of periods,the resonance depth increases;with the increase of depths of cladding,the resonance wavelength shifts to longer wavelength.

Cascaded diam-etched fiber was studied to realize the dynamic manipulation of dual-wavelength filter.Utilizing the coupled-mode theory and segmented transfer matrix method,the theoretical derivation and simulation calculation were carried out.A new type of tunable dual-wavelength filter was studied based on cascaded Acousto-Optic Gratings(AOGs) in diam-etched fiber.The side lobe suppression effect of diam-etched AOGs in the transmission spectra was analyzed.The results show that optical fiber etching method can effectively suppress the side lobe effect,the side lobe ratio can be decreased from 0.265 to 0.031;The dual-wavelength filter works symmetrically and efficiently with tunable frequency spacing by adjusting the fiber length.When the fiber length increases,left resonant wavelength peak decreases and right resonant wavelength peak increases.The wavelength of the dual wavelength filter tunable adjusted by the frequency of the acoustic signal and the number of segments of the fibers,the dual-wavelength increases with the acoustic wave,and approximately linearly between 270 μm to 282 μm,the wavelength shift enlarges with the number of fiber segments increasing.

In order to realize a dual-wavelength laser output,a ring cavtiy erbium-doped fiber laser based on fiber ring filter was proposed.In designed system configuration,one polarization maintaining-fiber Bragg grating was adopted as wavelength selector.The fiber ring filter was frabricated by two couplers with 20:80 splitting ratio and 2 m polarization maintaining fiber to constrain the mode hopping and improve the working stability,and the polarization controller inserted into the filter can be used to switch laser wavelengths.In order to guarantee the system stability,a saturable absorber of 1 m long was spliced between circulator and polarization maintaining-fiber Bragg grating.In the expriment,the working threshold is 71 mW,and the spectrum character of two lasres are improved after filter is used.The switchable single wavelength and two simultaneous wavelengths can be realized by adjusting the polarization controller,the wavelength space is 0.88 nm,and the maximum output power of single laser 1 535.5 nm and 1 534.7 nm is 0.078 dBm and -2.585 dBm,and 3 dB linewidth are 0.16 nm and 0.15 nm respectively.At room temperature,over 20 min scan time,the wavelength shifts are less than 0.06 nm ,the power fluctuation are less than 1.3 dB.

In order to observe high dynamic scene effectively and in real time,an imaging system based on digital micromirror device as a spatial light modulator was designed.The capability of digital micromirror device was improved in increasing the dynamic range of imaging system by improving the driving timing of digital micromirror device.To tackle the distortion error of the optical system,polynomial fitting was employed to acquire the mapping relationship between digital micromirror device and imaging sensor.Finally,in order to resolve the problem of poor visuality when using ordinary light adjusting algorithm,tone mapping operator was introduced to generate a light adjusting template and image with better visuality was acquired.The results indicate that the dynamic range of traditional imaging system can be increased by 66 dB under the condition of 10 frames per second and the total dynamic range of the imaging system reachs 126 dB.Morever,the precision of using digital micromirror device to control imaging sensor is up to 0.69 pixel,bright part and dark part in a high dynamic range scene can be displayed simultaneously in one image after light adjusting and the entropy of image collected after light adjusting inreased.The imaging system meet the requirement of real time observation in high dynamic range scene.

Digital micromirror device is added into the fluorescence confocal microscopy system,insteads of lighting pinhole of a traditional confocal microscopy system.The modulation properties of digital micromirror device divide a light source into multiple beams through loading different pictures on digital micromirror device.Four-channel,six-channel and nine-channel fluorescence images of photo cells were detected and the system resolution was analyzed by measuring the depth response curve.The experimental results show that the microscopy system transfers from point-to-point imaging into the parallel confocal microscopy imaging based on digital micromirror device.The system provides a fast scanning speed and a high resolution.

For the work of calibration and data retrieval of the wind field measuring Fabry-Perot interferometer,a method of nonlinear regression fitting combined with transfer function model was researched.First of all,the instrument transfer function and air-glow response model were established with a modified Airy function.Secondly,ground calibration was done to the Fabry-Perot interferometer system with a frequency-stabilized laser and the calibration data was collected.Nonlinear regression fitting step by step was applied to the processing of the calibration data to get parameters of the instrument transfer function.Finally,the wind and temperature of the simulated air-glow fringe,with different signal noise ratio,wind and temperature input,were estimated with the calibrated instrument transfer function model.The results show that the wind and temperature retrieval accuracy can excel 5 m/s and 10 K respectively for data with signal noise ratio better than 40.

There exist axis errors when using the digital zenith camera to orient in celestial positioning.In order to improve the precision of tilt compensation,the parameters of the tilt sensor were considered to get the exact data,and the influence of the parameters was analyzed.The result demonstrates that if the square of the two aixs scale is below 10-6,the influence can be ignored.The influence of tilt and the precision of station were also analyzed.The analysis of data got from experiments shows that when the tilt is above 100″,the precision of the parameter will be high,and if the error of the station is below 0.23″,the influence of tilt parameter can be ignored.

As the ideal structure model and accuracy analysis of existing four-light-screen optical target cannot meet the requirement of engineering design and development,a common engineering structure model was developed,and the measurement formulas and error transfer formulas were deduced.The influences of different parameters,such as the impact location,target distance,light-screen intersection angles and the size of sensor area,to the position measurement accuracy of system were analyzed through simulation.A series of position measurement error analysis data were acquired.The structure and theoretical error estimate results of a practical four-light-screen optical target were given.The live-fire testing result shows that the X and Y position measurement errors of this four-light-screen optical target system in a 1 m×1 m sensor area are less than 2 mm,which is close to the theoretical analysis result,and the result verified the correctness of the proposed engineering model and effectiveness of theoretical analysis.This research can provide useful reference for practical design and accuracy estimate of four-light-screen optical target.

In order to improve imaging quality of SiC reflective mirror,an improved scheme of traditional lightweight mirror and the corresponding optimization method were proposed.The scheme of variable rib thickness design for lightweight mirror was brought forward.Lightweight ribs were divided into different groups based on geometry position and force transferring route respectively,both schemes with grouping performed better than traditional structure in imaging quality,indicating that lightweight ribs with different topology relation played different roles in enhancing the stiffness of lightweight mirror.The ribs on the back of mirror were trimmed in order to improve local distortion in areas away from supporting holes.The integrated optimization model based on improved structure was built,using Multi-island Generic Algorithm to find the best combination of all the structure parameters.The simulation results show that after optimization,the grouping scheme based on force transferring route overmatches traditional design,with surface quality improved by 33.2%,and mass decreased by 11.7%.

The dynamic response of optical resonant cavity has been theoretically studied,by taking resonant cavity as a linear and time invariant system and through the approach of Signal Processing.The mathematical description obtained could fit any form of light waves.From the perspective of Signal Processing,the traditional pulse and continues wave cavity ring-down spectroscopy could be considered as observation of impulse response and step response respectively.Furthermore,the cavity response to the light-wave linearly frequency chirped has been studied,in the condition of slow chirp.The Fourier analysis of light power passed through cavity has been made and an analytic description has been given,which reveals the fact that the signal spectrum of light power is related to the absorption spectrum of material inside cavity.Based on this theoretic analysis,a new approach of cavity enhanced absorption spectroscopy has been put forward,called Frequency Domain Cavity Ring-Down Spectroscopy.The result would facilitates the research of cavity enhanced spectroscopy techniques,as well others using resonant cavity,such as P-D-H laser frequency stabilization.

The Dy3+ doped α-NaYF4 single crystals were synthesized by a modified Bridgman method under the conditions of taking KF as an assistant flux and a temperature gradient (70~90 ℃/cm) at the solid-liquid interface.X-ray diffraction,absorption spectra,excitation spectra,and emission spectra were measured to investigate the phase and spectrum properties of the crystals.The chromaticity coordinates and color temperature of crystals were calculated based on Colorimetry theories.Many growing experiments demonstrate that the chemical compositions of 30NaF-18KF-52YF3 (molar ratio) are beneficial to obtain big α-NaYF4 single crystals.The introduction of KF changed the phase equilibrium between NaF and YF3 completely and lowered the melting point of α-NaYF4,resulting into crystallization of α-NaYF4 just from the mixture when it is cooled.Most of KF was excluded on the top of crystals which grew at the final stage of crystal growth.The introduction of flux KF did not change the structure of α-NaYF4 single crystals.The emission blue 479 nm,yellow 571 nm and weak red 659 nm could be obtained simultaneously under the excitation of ultraviolet lights.A white light emission from the coupling of the above three lights with chromaticity coordinates of x=0.285,y=0.338,color temperature Tc=8 065 K could be obtained from 1.299 mole% Dy3+ doped α-NaYF4 single crystal when excited by a 348 nm light.This indicates that Dy3+ doped α-NaYF4 single crystals can be a potential candidate for white light emitting diode excited by ultraviolet light.

Er3+ single doped BaGd2ZnO5 phosphors with various Er3+ concentrations,Er3+/Yb3+ codoped BaGd2ZnO5 phosphors with various concentrations of Er3+ or Yb3+ were obtained via a traditional high temperature solid state method.Crystal structure of the obtained phosphors was characterized by means of X-Ray Diffraction,and it was confirmed that all products exhibited pure phase as BaGd2ZnO5,and that the doping concentration did not evoke change in crystal structure.The upconversion emission spectra for all samples with different rare earth ion concentrations were measured upon 980 nm excitation under the same experimental conditions.It was observed that the green upconversion intensity was larger than that of the red one in the Er3+ single doped phosphors,the red upconversion intensity was larger than that of the green one in the samples with fixed Yb3+ concentration of 20% and various Er3+ concentrations,moreover,the both green and red upconversion intensities are higher for the samples with fixed Er3+ concentration of 5% and various Yb3+ concentrations.The dependence of upconversion intensity on the laser working current (the different excitation power densities) was analyzed,and the two-photon process was confirmed to be responsible for the green and red emissions.The color coordinates for all the samples were calculated,and it is seen that the doping concentration greatly influenced the color coordinates which can be tuned by the rare earth ion doping concentration.

In order to investigate the mechanism and properties of photoluminescence of La1-xYO3:xPr3+ phosphors,the phosphors with various doping concentration were synthesized via a urea assisted solution-combustion method.The phosphors were characterized by X-ray powder diffraction,field emission scanning electron microscope and photoluminescence,respectively.The results show that the samples exhibit a cubic phase in crystal structure,and the strong green luminescence is emitted from La1-xYO3:xPr3+ phosphors under an excitation of ultraviolet light at 295 nm.The intensity of green photoluminescence emission is increased with the increasing of praseodymium concentration.Then it is decreased at higher concentration due to the concentration quenching effect.The optimum doping concentration of Pr3+ ions is about 1.0 mol% for attaining the strongest green photoluminescence emission.

The transparency and second harmonic properties of Al,S and Te doped GaSe crystals were studied.Low absorption coefficients of α≤0.1～0.2 cm-1 are found in crystals with suitable doping level in transparent range which can be used in nonlinear devices.High doping level is allowed in GaSe:S crystals whose transparency spectra shift towards to short-wavelength range.The short wavelength transparency cut-off of both Al and Te doped crystals shifts more slowly than S doped crystals towards to opposite direction.The optical quality of the crystals has declined markedly when the doping concentration up to GaSe:Al (0.5 mass%) and GaSe:Te (5 mass%).The phase matching curves shift towards to short-wavelength and output power is significantly higher in S doped GaSe crystals than that in pure GaSe crystals with fs Ti:Sapphire laser and CO2 laser pumping.The optimal doping concentration is ascertained as 2 mass%.No obvious differences of type I second harmonic phase matching angle between Al,Te doped and pure crystals are found.The experimental results are in good agreement with theoretical curve.GaSe:Te crystals are found to possess the hexagonal structure like ε-GaSe when the doping concentration is no more than 5 mass% with nonlinear method.The SHG efficiency ratio of the optimal doped crystals GaSe:Al (0.1 mass%),GaSe:S (2 mass%) and GaSe:Te (0.5 mass%) is about 1:0.6:0.5 under CO2 laser pumping.GaSe:S (2 mass%) crystal shows the best performance whose efficiency is about 3 times higher than that in pure GaSe among all used samples.

The tunable near-infrared laser with wavelength range of 1.1~2.2 μm was generated by the different- frequency generation.In the experiment,the optical system was constituted of tunable dye laser (560~710 nm) as the pump light source and 1.064 μm laser diode as the signal light source ,the efficient near-infrared radiation was generated by the temperature-tuned non-critical phase-matched type-Ⅰ difference-frequency mixing in a LBO crystal ,and the average output power was measured more than 30 mW during the near-infrared radiation.At 1.54 μm the output power was measured 35 mW in the condition of the 1.2 W of the pump source and 0.31 W of the signal source,and the energy conversion efficiency of 11.7% was achieved.The peculiarity of broadly tunable and narrow spectral bandwidth of the near-infrared of the different-frequency generation has an extensive application.

Au/Multiwalled Carbon Nanotubes(Au/MWCNTs) composites were synthesized by a chemical adhesion method.The composites were characterized by X-ray diffraction,UV–vis absorption and transmission electron microscopy,which demonstrated that Aunanoparticles with an average diameter of about 6 nm covered the MWCNTs surface.The third-order optical nonlinearities of MWCNTs and Au/MWCNTs composites were investigated using picosecond Z-scan technique at 532 nm.The third-order nonlinear susceptibility χ(3) of Au/MWCNTs composite was calculated to be 1.89×10-12 esu,which was 2.6 times larger than that of MWCNTs.

The filtering characteristics of one-dimensional photonic crystal with an air defect layer were investigated using transfer matrix method as the thickness of defect,incident angle and thickness perturbation changing.The studies suggest:For air thickness adjustable structure,considering the dispersion of the materials,the increase of 2 nm for the air thickness makes the transmission peak shift about 2 nm to the long-wave direction,which shows a linear relationship of 1:1;For incident angle adjustable structure,compared with the normal incidence,when the incident angle change from 0° to 89°,the omnidirectional photonic bandgap decrease 105 nm (TE mode)、600 nm (TM mode) respectively;which shows that TM mode band gap are greatly influenced by the change of incident angle;it can realize the tunable filter in C band when the incident angle varies from 0° to 16.9° (TE mode) and 17.0° (TM mode) respectively.In the same period,the mutual remedying of thickness error of two materials can realize insensitivity to thickness perturbation in small range,which can narrow the deviation between the actual peaks and theoretical peaks to reduce the difficulty of the fabrication of photonic crystal.

The influence of the working temperature on the Current Balance Factor(CBF) value of the single layer Organic Light Emitting Diodes(OLEDs) was investigated by utilizing a numerical model of a bipolar single layer OLED with organic layer level traps.Results show that the largest CBF value can be achieved when the electron injection barrier (n) is equal to the hole injection barrier (p) in the lower working temperature region at any instance.In the higher working temperature region,the largest CBF can be achieved in the case of n >p under the condition of electron mobility (μ0n) larger than hole mobility (μ0p),whereas the result for the case of μ0n<μ0p,is the opposite.When μ0n=μ0p,the largest CBF can be achieved in the case of n=p in the entire region of the working temperature.In addition,the CBF value of the device increases as working temperature increasing.The results obtained in this paper can present an in-depth understanding of the OLEDs working mechanism.

To improve the efficiency of phase modulator,the ring resonator which is equivalent to Maher-Zehnd′s upper and lower arm was proposed by combining the advantages of the optical microring and Mach-Zehnder.The normalized output intensity and output phase were derived by coupled-mode theory.The effects of the transmission loss factor and the coupling angle on the normalized optical intensity and phase were numerically analyzed.The analysis results show that the output light spectrum cyclical changes as phase-sensitive ring phase changes.When the coupling angle increases,the output light spectrum becomes more acute,the output of π need the greater phase modulation.When the transmission factor is small,the phase change is relatively flat spectrum,the difference between maximum and minimum values is not met π.By optimizing structure parameters of Mach-Zehnder microring resonator,sensitive ring structure can improve the modulation efficiency.Simulation results show that when the phase shift of the sensitive ring is 0.1π,the output phase shift can be achieved π,and the normalized intensity can be kept 0.9 at the same time.The consistent requirements of phase shift and signal amplitude in differential phase shift keying is implemented,which providing a theoretical basis for further study of phase modulator.

The suppression of laser excess noise using a cascaded imbalanced Mach-Zehnder interferometer with fiber optic components was proposed and demonstrated in the experiment.By developing an automatic phase control system,the phase of the fiber interferometer with a large path imbalance (127 m) can be stabilized in a long term,and the laser excess noise around 800 kHz and its integer multiples can be efficiently suppressed by more than 45 dB.The effective frequency bands of the noise filter can be controlled by adjusting the arm-length difference of the interferometer.The approach provides an effective solution for achieving compact and cost-effective laser noise reduction,and can be applied directly to the quantum optomechanical system where shot-noise-limited laser can be required.

The diffusion master equations of density operators under action of linear resonance force were concisely solved by virtue of thermo entangled state representation and the technique of integration within an ordered product of operators.The evolution formula of the field density operator was given,and the Wigner function evolution formula which is in superposition of vacuum state and single-photon state initially was obtained.By numerically calculating the Wigner function was plotted,and the evolution of negative volume of Wigner function with dissipation time was calculated.Through the analysis of the Wigner function,the effect of decoherence on nonclassical property of the state was discussed.Numerical results show that the negativity area size and the depth of negativity of its Wigner function decrease until vanish with dissipation time.In addition,on the other hand,Wigner function can be slipped under the action of linear resonance force.

The steady state energy spectrum of Tavis-Cummings model without rotating wave approximation using displaced coherent state method was studied.And the influence of initial state and coupling strength to concurrence were numerically studied.Our result demonstrates that the ground state of the system is non-degenerate with an exchange-symmetry between two atoms.The entanglement between two atoms always keeps maximal when the initial state is set to anti-symmetric while the non-entangled initial state produce entanglement periodically due to the effect of non-rotating terms.The coupling strength between the cavity field and atoms play a critical role in the entanglement dynamics.

The ultra-broad band anti-reflection film in 1 300~3 400 nm has been designed and fabricated on acousto-optic crystal.Using electron beam vacuum deposition system and Utilizing technology of co-evaporation of two materials,some obstacles have been overcome,such as obtaining right refractive index from limited materials,eliminating unwished absorption in corresponding band,Absorption is reduced to 0.7%.Through tests,it was found that during the process of co-evaporation,when the material with less stable evaporation rate was evaporated in the first place,and the more stable material wasn′t set to start evaporation until the former material get a steady evaporation rate,the mass ratio of two materials can get tremendous improvements,which is helpful in obtaining the expected index of refraction as well.This method was tested to be feasible through theoretical simulation.The average transmissivity of film prepared in the corresponding band is over 96% ,the film meetenvironment requirements.

Hg1-xCdxTe graded-gap films were grown by the method of vaper phase epitaxy,and the transverse composition non-uniformity of the films was researched by infrared transmission spectra.Applying the multilayer model and transfer matrix,the infrared transmission spectra and compositional profiles of the HgCdTe epilayers were calculated,the calculated values were consistent with the experimental results.The theoretical calculated compositional profile of the vaper phase epitaxy layers was corresponding to variation tendency of the experimental data measured by energy spectrum.Based on traditional photovoltaic technique,the 10×1 linear focal plane arrays detectors were prepared by using Au-doped Hg1-xCdxTe film materials.Performances of the detectors are favorable,and the detectivity of the detector can be achieved 4.20×1011/ (cm·Hz1/2·W-1)@95 K.

The CdS thin films were prepared by chemical bath deposition in a solution containing cadmium chloride,ammonium chloride,thiourea and ammonia.The morphological,structural and optical properties of CdS films were investigated by scanning electron microscope,X-ray diffraction and UV-vis-NIR spectroscopy.The photo-current response curves were also tested to study the optoelectrical performance of the films.It was found that uniform and compact CdS films could be prepared using pH values from 9 to 11.The CdS film prepared at pH=10 showed a most dense surface morphology and presented strongest peak intensities of the X-ray diffraction patterns and a band gap of about 2.37eV.According to photo-current response results,the CdS film with best quality has a highest photoconductivity of 2.94×10-2 Ω-1·cm-1 and a largest light and dark conductivity ratio of 38.23.