This PDF file contains the front matter associated with SPIE Proceedings Volume 9284, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

To adapt the specific demands of photomultiplier tubes (PMTs) in the Jiangmen Underground Neutrino Observatory, we design and manufacture a new type of micro-channel plate PMT (MCP-PMT) with the following performance indicators: the PMTs’ glass shell adopts the formula of GG-17 which have no K₂O, and very low background (the contents of ²³²Th, ²³⁸U and ⁴⁰K in the raw materials are less than 40 ppb, 20 ppb and10 ppb, respectively). Its main body is sphere with 500 mm external diameter, 4 mm wall thickness and the tails that using a gradual transition of kinds of low radiation background glasses, then sealing with the Kovar. The photocathode material with lowest dark noise is bi-alkali photocathode which spectral region matches the liquid scintillator emission spectral (400~440 nm). The front and back hemisphere is transmission and reflective photocathode separately. Two sets of double-stack micro-channel plates replacing the dynode chain are used to detect the photoelectrons from both sites. The focusing system makes the photoelectrons hit into the inside of MCPs to the uttermost. The anode and lead make sure charge signal is no distortion. No matter made by transfer equipment or not, the peak value of quantum efficiency of the PMT should reach 30%, and the peak-to-valley ratio of single photoelectron spectrum has surpassed 2.5:1. In a word, the MCP-PMT’s reliability and other characteristics meet the need of Jiangmen Underground Neutrino Observatory.

Nanowire grating is designed within the wavelength range from 1μm to 3μm according to the sensitive wavelength of InGaAs short wave infrared (SWIR) detector. The polarization performance is analyzed on the basis of finite difference time domain (FDTD) method. In order to improve the polarization performance, we insert a SiO₂ dielectric grating between metal grating and substrate to form Au-SiO₂ hybrid grating. The numerical study shows transmittance of hybrid grating is almost 88％which is 18％ higher than monolayer metal grating at 1.8μm. In addition, the hybrid grating with the grooved- SiO₂ layer has higher transmittance efficiency than those with smooth SiO₂ layer for special wave band. By optimizing the specific parameters of the hybrid grating such as period, thickness and the groove depth of SiO₂, finally we obtain the optimal parameters of the designed hybrid grating: the grating period is 0.4 μm, the thickness and groove depth of SiO₂ are 0.4μm and 0.1μm respectively. Numerical study shows that the designed grating has advantages of wide band, high transmittance efficiency and high extinction ratio.

The non-doped orange-red phosphorescent organic light-emitting device (PHOLED) based on a newly synthesized iridium complex, bis[2-(biphenyl-4-yl)benzothiazole-N,C²']iridium(III)(acetylacetonate) [(4Phbt)₂Ir(acac)] has been demonstrated. The non-doped device with (4Phbt)₂Ir(acac) as the emissive layer achieved ideal turn-on voltage (<4 V) and superior power efficiency (5 lm/W) as well as luminance efficiency (6 cd/A), respectively. Our device performance indicates that (4Phbt)₂Ir(acac) possesses excellent self-quenching-resistant property. The potential of this property is originated from the introduction of bulky and twisted aromatic substituents in ligands, which break the molecular planarity and obstruct the molecular packing. Besides, the high electroluminescence efficiency is also attributed to that the energy level alignment between (4Phbt)₂Ir(acac) and adjacent charge-transporting materials forms a well-like structure, which confines exciton effectively in emissive layer.

We demonstrated ultraviolet organic photodetectors based on poly(N-vinylcarbazole) polymeric matrix (PVK) and phosphorescent material of bis[2-(4-tertbutylphenyl)benzothiazolato-N,C2'] iridium(acetylacetonate) [(t-bt)₂Ir(acac)] blend film. The structures are the indium-tin oxide (ITO)/PEDOT : PSS/PVK/Bphen/Ag and ITO/PEDOT : PSS/PVK : (t-bt)₂Ir(acac) (1 : 10 %wt)/Bphen/Ag. Under UV light illumination, a high photocurrent density of 3.44 mA/cm² at -4 V was obtained, which is 6.6 times higher than that of without (t-bt)₂Ir(acac) material. The superior performances of the device doped with (t-bt)₂Ir(acac) material resulted from the UV light absorption efficiency and triplet nature of the phosphorescent complex.

The single-pixel extended wavelength mesa InGaAs/InAsP SWIR detector was reported. The properties of the detector were characterized and analyzed at 160K~300K. At the operating temperature of 200K , the dark current density is 1.37×10⁴ nA/cm²(@-10mV), the cut-off wavelength is 2.43μm, the peak detectivity and the peak responsivity are 3.44×10¹¹cmHz^1/2W^-1 and 1.41A/W, respectively. Through analysis of the dark current source, the analysis of reverse dark current indicates that the tunneling current plays an important role at high voltage or relatively low temperature, and at near room temperature and low bias voltage, the generation-recombination current is the main current source instead of ohmic current based on thermal activation energy approximate to E_g/2 and the bias-voltage characteristic of the first order derivative of dark current, while the zero-voltage current mainly consists of the interface current and the thermal background current.

1.064 μm, 1.319 μm and 10.6 μm laser were used to irradiate silicon-based HgCdTe CCD image system. The temperature distribution of detector induced by infrared laser irradiating in the experiment above was simulated. The influence of temperature on photoelectric parameters of HgCdTe CCD was calculated. A CCD physical model of crosstalk saturation was built and the response characteristic of CCD under the influence of thermal noise was analyzed. Result indicated that the rise of temperature induced by laser irradiating little influenced imaging effect of CCD.

In this article the transmission characteristics of laser in multilayer coatings are analyzed. The work consists of two parts: First, electric field intensity distribution in a coating designed of A/H (LH)^N/G structure is simulated numerically. Second, electric field intensity distribution in multilayer coatings designed of different N or optical thickness are further analyzed. The results show that：In the coating designed of A/H (LH) ^N/G structure, the maximum values of intensity decrease layer-by-layer at a definite ratio. The extreme values of intensity occur at the interfaces between layers. In the multilayer coatings of N=5, 10, 15, the extreme values of intensity occur at the interfaces changelessly. As N increases, the reflectance of multilayer coating approaches to 100%. In the multilayer coating of thicker optical thickness, the extreme values of intensity occur at the inner of each layer. As optical thickness increases, the reflectance decreases.

For the existing drawbacks of traditional detecting methods which use gratings or prisms to detect light intensity distribution at each wavelength of polychromatic light, a novel method based on multi-quantum wells spatial light modulator (MQWs-SLM) has been proposed in this paper. In the proposed method, MQWs-SLM serves as a distribution features detector of the signal light. It is on the basis of quantum-confine Stark effect (QCSE) that the vertical applied voltage can change the absorption features of exciton in multi-quantum wells, and further change the distribution features of the readout polychromatic light of MQWs-SLM. It can be not only an universal detecting method, but also especially recommended to use in the Electronic nose system for features detecting of signal light so as to realize smell sensing and visualizing. The feasibility of the proposed method has been confirmed by mathematical modeling and analysis, simulation experiments and research status analysis.

Hydrogenated amorphous silicon germanium (a-SiGe:H) single junction pin sequence solar cells with different bandgap structure of intrinsic layer were prepared by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD). Three kinds type of intrinsic layer using in this study were non-grading structure, V type grading and reverse V type grading. The effects of different intrinsic layer structure on solar cell performance were systematically studied. The results showed that the optimized structure of intrinsic layer was the reverse V type grading structure. And the performance of a-SiGe:H solar cell with reverse V type grading after annealing also were studied. The results revealed that the performance was improved after first annealing, but was deteriorate for further annealing. And, we have studied the dark I-V curves in order to contribute to a better understanding of the basis of solar cells.

In this paper the mechanism of BBO crystal component for frequency resolved optical gating technique has been researched by mathematical modeling and Simulation. Research shows that thickness of the crystal and the phase matching angle are important parameters affecting the measurement performance. Crystal thickness determines the pulse width limit which this crystal can distinguish; when the phase condition is matched between the fundamental frequency and second-harmonic of light, the SHG efficiency of incident light is highest. According to the calculations, An BBO crystals with 3.5mm thickness, 20.56 degrees phase matching angle is adopted to realize the crystal component for tens to hundreds of femtoseconds pulse width measurement.

We fabricated the inverted polymer solar cells (PSCs) with a structure of ITO/ZnO/PTB7:PC₇₁BM/MoO₃/Ag, and investigate the influence of spin coating on the device performance in this article. Through modifying the spin coating parameters, the high PSC performance could be obtained with V_OC=0.769 (V), J_SC=11.6 (mA/cm²), FF=58.8 % and PCE=5.26 %, respectively. The improvement of device performance was attributed to the enhanced absorption of active layer in the wavelength from 550 nm to 700 nm and the increased phase separation of PTB7:PC₇₁BM.

The calculation of star point centroid is a key step of improving star tracker measuring error. A star map photoed by APS detector includes several noises which have a great impact on veracity of calculation of star point centroid. Through analysis of characteristic of star map noise, an algorithm of calculation of star point centroid based on background forecast is presented in this paper. The experiment proves the validity of the algorithm. Comparing with classic algorithm, this algorithm not only improves veracity of calculation of star point centroid, but also does not need calibration data memory. This algorithm is applied successfully in a certain star tracker.

An image restoration method based on Poisson-maximum likelihood estimation method (PMLE) for earthquake ruin scene is proposed in this paper. The PMLE algorithm is introduced at first, and automatic acceleration method is used in the algorithm to accelerate the iterative process, then an image of earthquake ruin scene is processed with this image restoration method. The spectral correlation method and PSNR (peak signal-to-noise ratio) are chosen respectively to validate the restoration effect of the method, the simulation results show that iterations in this method will effect the PSNR of the processed image and operation time, and this method can restore image of earthquake ruin scene effectively and has a good practicability.

Polymer:fullerene bulk-heterojunction hybrid solar cells with the structure indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate)(PEDOT:PSS)/poly(3-hexylthiophene)(P3HT):[6,6]-phe nylC61-butyric(PCBM)/bathophenanthroline(Bphen)/Ag were fabricated. In this paper, the electrical characteristics of bulk heterojunction organic solar cells with various thickness of P3HT:PCBM as the active layer and Bphen as an exciton-blocking layer(EBL) were studied. The results showed that the P3HT:PCBM layer at about 110nm perform best, the open circuit voltage(V_oc) , short circuit current(J_sc) and the power conversion efficiency(PCE) reach to 0.57V, 10.82mA/cm², 2.50%, respectively; then when Bphen was 1nm, Voc is 0.56V, J_sc is 12.64mA/cm², PCE reach the maximum 3.30%.

A novel color correction method of camera based on HSV (Hue, Saturation, and Value) model is proposed in this paper, which aims at the problem that spectrum response of camera differs from the CIE criterion, and that the image color of camera is aberrant. Firstly, the color of image is corrected based on HSV model to which image is transformed from RGB model. As a result, the color of image accords with the human vision for the coherence between HSV model and human vision; Secondly, the colors checker with 24 kinds of color under standard light source is used to compute correction coefficient matrix, which improves the spectrum response of camera and the CIE criterion. Furthermore, the colors checker with 24 kinds of color improves the applicability of the color correction coefficient matrix for different image. The experimental results show that the color difference between corrected color and color checker is lower based on proposed method, and the corrected color of image is consistent with the human eyes.

For varied doping GaN photocathode, from bulk to surface the doping concentrations are distributed from high to low. The varied doping GaN photocathode may produce directional inside electric field within the material, so the higher quantum efficiency can be obtained. The photoemission surface of varied doping GaN photocathode is very important to the high quantum efficiency, but the forming process of the surface state after Cs activation or Cs/O activation has been not known completely. Encircling the photoemission mechanism of varied GaN photocathode, considering the experiment phenomena during the activation and the successful activation results, the varied GaN photocathode surface model [GaN(Mg):Cs]:O-Cs after activation with cesium and oxygen was given. According to GaN photocathode activation process and the change of electronic affinity, the comparatively ideal NEA property can be achieved by Cs or Cs/O activation, and higher quantum efficiency can be obtained. The results show: The effective NEA characteristic of GaN can be gotten only by Cs. [GaN(Mg):Cs] dipoles form the first dipole layer, the positive end is toward the vacuum side. In the activation processing with Cs/O, the second dipole layer is formed by O-Cs dipoles, A O-Cs dipole includes one oxygen atom and two Cs atoms, and the positive end is also toward the vacuum side，thus the escape of electrons can be promoted.

Star identification is the key problem of satellite attitude determination from star sensor. Since star angular distance is directly used as matching feature in traditional star identification, the precision and success rate of traditional method are highly dependent on the calibrated accuracy of the star camera parameters. In this paper, a star identification algorithm is improved. The algorithm uses interior angles of a triangle composed of observation stars as matching feature. The triangles composed by nautical star and observed star are homothetic. Interior angles of triangle are independent from both the focal length f. Thus this method is not dependent on camera parameters, and the position information is unnecessarily priori. Monte Carlo experiment shows that the probability of failing Star identification is less than 6.63%. Generally, the time of star identification process is restricted to 30ms. In addition, it can work well within the 50% error of f. Compared with traditional algorithm; this algorithm has advantage on successful identification rate and reliability.

White organic light-emitting devices (WOLEDs) with combined doping emissive layer (EML) and ultrathin EML have been fabricated to investigate the effect of each EML on the electroluminescent (EL) performance of the WOLEDs. Through tailoring doping concentration of bis[(4,6-difluorophenyl)-pyridinato-N,C2’](picolinate) iridium(III) (FIrpic) and thickness of ultrathin bis[2-(4-tertbutylphenyl)benzothiazolato-N,C2’] iridium (acetylacetonate) [(tbt)₂Ir(acac)] EML, it is found that the change in the doping ratio of FIrpic significantly influenced the EL efficiencies and spectra, while the alteration of ultrathin EML thickness had much milder effect on the EL performance. The results indicated that ultrathin EML is in favor of reproducibility in mass production compared with doping method.

This study analyzes the measurement errors of three dimensional coordinates of binocular stereo vision for tomatoes based on three stereo matching methods, centroid-based matching, area-based matching, and combination matching to improve the localization accuracy of the binocular stereo vision system of tomato harvesting robots. Centroid-based matching was realized through the matching of the feature points of centroids of tomato regions. Area-based matching was realized based on the gray similarity between two neighborhoods of two pixels to be matched in stereo images. Combination matching was realized using the rough disparity acquired through centroid-based matching as the center of the dynamic disparity range which was used in area-based matching. After stereo matching, three dimensional coordinates of tomatoes were acquired using the triangle range finding principle. Test results based on 225 stereo images captured at the distances from 300 to 1000 mm of 3 tomatoes showed that the measurement errors of x coordinates were small, and can meet the need of harvesting robots. However, the measurement biases of y coordinates and depth values were large, and the measurement variation of depth values was also large. Therefore, the measurement biases of y coordinates and depth values, and the measurement variation of depth values should be corrected in the future researches.

The basic principle and formation of the auto-gated power using hybrid automatic brightness control scheme were described in detail. The auto-gated power supply in the application process because the device precision and the low-light level image intensifier between individual differences, fall may cause some products in some cases the SNR and resolution, and decrease the consistency of the product. This paper puts forward the corresponding solutions to these problems. And through experiments on the improved auto gated power supply with automatic gated power has not been improved compared. Applications of the auto-gated power in military, police and civil area were forecasted.

Phosphorescent materials are crucial to improve the luminescence and efficiency of organic light emitting diodes, because its internal quantum efficiency can almost up to 100%. So the studying of optical and electrical properties of phosphorescent materials is propitious to the further development of phosphorescent OLED. Phosphorescent materials were generally doped into different host materials as emitting components, not only played an important role in emitting light but also had a great influence on carrier transport properties. (t-bt)₂Ir(acac) was a common yellow phosphorescent material. The optical and electrical properties of the blue DPVBi-based devices, adding (t-bt)₂Ir(acac) in different position, have studied. The results showed (t-bt)₂Ir(acac) has remarkable hole-trapping ability. Especially the ultrathin structure device, compared to the device without (t-bt)₂Ir(acac), had increased the luminance by about 60%, and the efficiency by about 97%.

As the focusing range of optical imaging system is generally limited, it is difficult to make all the objects of the same scene clearly shown in one image. Besides, a case usually rose that the fused image with a high entropy, however, is not satisfying for vision effect. In this paper, a new method of multi-focus image fusion based on adaptive dividing blocks using comprehensive index was proposed, in which the comprehensive index was on basis of spatial frequency and entropy. The comprehensive index is better with the higher spatial frequency and entropy. Firstly, the registered original images were divided into a series of blocks of which the sizes were proper and the same, and then the comprehensive index for each block of source images was calculated as the focus criterion function to select an optimal block for each corresponding block of the fused image. In view of the relevance between pixel and pixel in one image, the optimal blocks selected were fused with a global fusion function. Furthermore, the sum-modified-Laplacian of fused image was used as the measure function to supervise the adaptive blocking, in which the optimal block was obtained when SML of the fused image had reached a high value or the iteration had achieved the specified numbers. Finally, the optimal size of the sub-block was automatically obtained, which was used to fuse the source images. As it was shown in the experimental results, the proposed method which was simple, but more effective compared with the traditional multiscale decomposing methods such as wavelet transform, wavelet packet transform, contourlet transform and so on. At the same time, the proposed method was also superior to the method in the literature for it could remove boundary discontinuities between image blocks. Contemporarily, much more details and edges information of the source images were reserved in the fused image.

Compressed sensing theory is a new sampling theory that can sample signal in a below sampling rate than the traditional Nyquist sampling theory. Compressed sensing theory that has given a revolutionary solution is a novel sampling and processing theory under the condition that the signal is sparse or compressible. This paper investigates how to improve the theory of CS and its application in imaging system. According to the properties of wavelet transform sub-bands, an improved compressed sensing algorithm based on the single layer wavelet transform was proposed. Based on the feature that the most information was preserved on the low-pass layer after the wavelet transform, the improved compressed sensing algorithm only measured the low-pass wavelet coefficients of the image but preserving the high-pass wavelet coefficients. The signal can be restricted exactly by using the appropriate reconstruction algorithms. The reconstruction algorithm is the key point that most researchers focus on and significant progress has been made. For the reconstruction, in order to improve the orthogonal matching pursuit (OMP) algorithm, increased the iteration layers make sure low-pass wavelet coefficients could be recovered by measurements exactly. Then the image could be reconstructed by using the inverse wavelet transform. Compared the original compressed sensing algorithm, simulation results demonstrated that the proposed algorithm decreased the processed data, signal processed time decreased obviously and the recovered image quality improved to some extent. The PSNR of the proposed algorithm was improved about 2 to 3 dB. Experimental results show that the proposed algorithm exhibits its superiority over other known CS reconstruction algorithms in the literature at the same measurement rates, while with a faster convergence speed.

The fabrication and characterization of InGaN ultraviolet photodetector were reported in this work. The effects of thermal annealing were investigated on the properties of ohmic contact. Experiments showed that the zero bias resistance was lowest when the sample was annealed at 550 degrees Celsius for 5 minutes. The current-voltage (I-V) curve showed that current at zero bias was 3.70×10^-13A and the resistance was 4.53×10¹⁰ Ω. A flat band spectral response was achieved in the 360nm~390nm. The detector displayed an unbiased response of 0.22A/W at 378 nm, corresponding to an internal quantum efficiency of 88%. R₀A values up to 1.3×10⁸Ω·cm² was obtained corresponding to D^*=1.97×10¹³cm•Hz^1/2•W^-1.

Trajectory prediction is essential for the maneuvering target tracking. Nowadays, one of the major challenges for precise prediction of position and velocity of one maneuvering target is the mismatching of target motion model and the movement mode the target performs. In order to solve this problem, the interacting multiple model method is proposed, which is able to adopt the current model to match the target motion mode so that the precision of prediction can be improved. One of the major problems of the interacting mult iple model methods is the selection of models for the algorithm. In this paper, such three models as constant velocity model, exponential increasing accelerat ion model, and the generalized coordinated turn model is selected. Afterwards, one simulat ion to verify the validation of the algorithm is performed, and it indicates that the interacting mult iple model methods with the specific models utilized in this paper does have the ability to track maneuvering target quite precisely.

There are several advantages offered by free space optic systems compared with conventional radio frequency systems. As a consequence of shorter wavelengths, the high directivity of the transmitted beam makes acquisition and pointing difficult, thus an imaging system is set up for acquisition and pointing. Optical wave front distortions induced by atmospheric turbulence result in a spreading of the beam leads to image jitter take place in the focal plane, where the image sensor is. The behavior of the image jitter can be described in a statistical manner. Consequently, the size, which is a very important parameter to an image sensor, can be determined by the statistical quantity of image jitter, which customarily is the root mean square (RMS) image displacement. The quantity of the RMS image displacement is as a function of several measurable parameters. In this paper, variations of the estimated RMS image displacement were calculate and discussed in detail. The calculation showed good agreement with the experimental results conducted with a propagation path length of 96 km. The optimal sizes of image sensors that are used for some specific circumstances were analyzed and proposed based on the RMS image displacement.

Black silicon has a wide spectrum of non-spectral characteristics high absorption from visible to long wave infrared band .Based on semi-empirical impurity band model, free carrier absorption, radiation transitions between the valence band and the impurity band, radiation transitions between the impurity band and the conduction band were calculated, and absorption coefficients for each process were got. The results showed that the transitions from valence band to the impurity band induced absorption in the near-infrared waveband, but it has a rapid decay with wavelength. In the shortwave mid-wave and long-wave IR bands, transitions from the impurity band to the conduction band caused a huge absorption, and the absorption coefficient was slowly decreased with increasing wavelength. The free carrier absorption dominates in long-wave band. The calculation results agreed well with the test results of plant black silicon in magnitude and trends.

High and low temperature activation experiments were carried out for a transmission-mode GaAs photocathode sample, and the activation photocurrent curves were recorded. The variety of the activation photocurrent curves between high and low temperatures was studied. By using fitting calculation, the surface potential barrier parameters of NEA photocathode after high and low temperature activations were obtained, respectively, and the change of the surface potential barriers between high and low -temperature activations is indicated. Besides, The NEA cathode surface after high-temperature activation and low temperature activation were analyzed respectively by using angle-dependent X-ray photoelectron spectroscopy (XPS). Above investigation results indicate that, with contrast to high-temperature activation, the thickness of surface potential barriers after low-temperature activation become thin and the vacuum level is reduced further. As a result, the cathode spectral sensitivity is improved remarkably.

Various spectroscopy techniques such as absorption, photoluminescence and photoinduced absorption (PIA) spectroscopy, were used to study the photophysics in poly [2-methoxy-5-(20-ethyl-hexyloxy)-1, 4-phenylenevinylene] (MEH-PPV) films, which were dropped cast on glass substrates using its toluene solution and being annealed at various temperatures. With the analysis of temperature dependence PL intensities, we conclude that PL emission around 680 nm at low temperature is due to intertain excimers instead of intrachain excitons for 450 K annealed film；On the other hand, this relative intensity difference is much smaller in both unannealed and 500 K annealed films, in which the morphology is amorphous and microcrystalline, respectively. We conclude that the interchain photoexcitations play crucial roles in the photophysics of MEH-PPV films. The further measurements on PIA spectrum of MEH-PPV films suggest that the interchain photoexciation is also important for the generation of triplet excitons.

The long lived phtoexcitation (polarons) dynamics that range from microseconds to milliseconds in a typical organic photovoltaic (OPV) material, the blends of regio-regular poly (3-hexylthiophene) (RR-P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), have been investigated using continuous-wave photoinduced absorption (cw-PIA) spectroscopy. In this time regime, whether above-gap (AG) or below-gap (BG) excitation, the delocalized polarons (DP) and localized polarons (LP) all exhibit dispersive bimolecular recombination process which is limited by multi-trap states; however, compared to AG, BG excitation presented the narrower distribution profile in trap polaron states. Furthermore, the recombination in RR-P3HT/PCBM films was weak temperature dependence with small thermal activation energy, the value Δ for DPs and LPs of 25 meV (45 meV) and 13 meV (42 meV) using AG (BG) excitation, respectively. We considered that polarons from BG excitation are not intrinsically different with polarons from AG one in millisecond time regime, therefore may contribute to the power conversion efficiency using appropriate materials and device structures. For completeness, cw-PIA spectroscopy of poly[2-methoxy, 5-(2’-ethyl-hexyloxy)-p-phenylene-vinylene] (MEH-PPV) and PCBM blended films with amorphous morphology were also studied. It is found that polarons also exhibited multi-trap limited bimolecular recombination, but Δ for polarons in amorphous MEH-PPV/PCBM was up to ~160 meV. We concluded that polarons in RR-P3HT/PCBM blend are basically transport by tunneling, but the recombination in MEH-PPV/PCBM blend near room temperature is mainly thermal activated process. Overall, it is demonstrated that cw-PIA spectroscopy with thermal-activated-recombination analysis can be applied to evaluate polymer (dis)order in bulk heterojunction films.

π-conjugated polymers (PCPs) are attractive candidates as gain media in laser applications due to their high photoluminescence quantum efficiency in broad spectral range. However, the self-absorption of long-lived excited states was considered to be a limitation for achieving more effective organic lasers. Moreover, the morphology of films is found to be crucial to their optical and electrical properties recently. In this work, we studied amplified spontaneous emission (ASE) of a typical PCP, namely, Poly [2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV) films with a 10 ns 532 nm pulse laser focused by a cylindrical lens for obtaining an excitation area in the form of a 100 μm wide and 1 cm long stripe. In an as cast MEH-PPV film, the thresholds increase with the temperatures increase due to the thermal torsion and vibration mode shorten the conjugation chain. On the other hand, a MEH-PPV film which is annealed in Nitrogen at 350 K of half hour, the ASE is not observed at both 300 K and 77 K, for annealing will form π- stacks which increase the interchain interaction. Further analysis suggests that interchain excimers instead of intrachain excitons may be more primary to optical properties in annealed MEH-PPV film. Our measurements suggest that the morphology of the film instead of long lived photoexcitation with lifetime sensitive to the temperature is more crucial to threshold of ASE, as well as, to PCPs lasers.

Depth Image Based Rendering (DIBR) technology is one of effective methods to generate stereoscopic image pairs in 3D image warping, however, the holes would be produced when using this method. Hole-filling algorithms are essential for improving image quality of stereoscopic image pairs. In this paper, a new hole-filling algorithm based on pixel labeling is proposed. Firstly, holes in stereoscopic image pairs produced by DIBR are marked as 0, whereas marked as 1. Then traversing the image pairs only once to fill pixel values of each hole according to the situation of hole’s eight neighborhood pixels, the hole would be filled by the average of no-hole pixel values when the number of no-holes greater than threshold, otherwise the hole is filled by the cross diamond search algorithm from every direction to find the closest no-holes until the number of no-holes greater than threshold. The proposed method is evaluated by existing objective assessment methods, such as PSNR and SSIM. Experiment results show that the proposed hole-filling algorithm provides an improvement in both of subjective and objective assessment by compared with the conventional hole-filling algorithm under the same source images. The proposed algorithm is not only simple, but also can effectively eliminate the holes generated by using the DIBR method.

The 3^rd generation low-light-level image intensifiers should be aged for 100 hours before its normal use. In order to know the influence of ageing processing on GaAs photocathodes, five 3^rd generation low-light-level image intensifiers were aged with the life testing instrument of low-light-level image intensifier in an experiment. With the spectral response testing instrument, the intensifiers were measured for totally 8 times to get their spectral response respectively before they were aged and in a half year after aged, and to calculate the integral sensitivity according to the spectral response curves. Based on the fluctuating spectral response curves and the varying integral sensitivity, it was indicated that the aged intensifiers up to standard had more stable photocathode sensitivity, smaller decrease in their spectral response curves, while those not up to standard had more obvious decline as a whole in their spectral response curves. Additionally, the threshold wavelength of all intensifiers was moving toward shortwave. The degeneration of GaAs photocathode resulted from the instability of the Cs-O layer on GaAs photocathode surface. During the ageing processing, the lack of a longtime light radiation on Cs-O layer, the widening surface barrier and the decreasing escape probability led to less photoelectronic emission and lower sensitivity. Moreover, the destruction of dipole layer resulted in smaller bending of surface band and higher vacuum level, so that the electrons in impurity level could not escape and the threshold wavelength moved toward shortwave. Thus the ageing processing played a role of picking out the 3^rd generation low-light-level image intensifiers to get rid of the products not up to standard and to put the photocathodes of products up to standard into a relatively stable random failure period.

The gallium arsenide (GaAs) photocathode was generally cleaned by radiant heating, direct heating, ion bombardment annealing, and so on. In this paper, the radiant heating method, namely thermal cleaning method, was adopted for GaAs photocathode surface purification. Using this method could obtain an atomic clean surface, ensure the integrity of the GaAs surface lattice, and guarantee the uniformity of surface cleaning effect at the same time. But because the accurate measurement of the GaAs photocathode surface temperature in the vacuum system was very difficult, the residual gas analyzer (RGA) was used in this experiment to monitor the residual gas composition in ultrahigh vacuum during the thermal cleaning process and determine the thermal cleaning temperature by the partial pressure curves of As and Ga. It was found that the first peaks of As and Ga elements both appeared after heating about one hour, accompanied with H₂O, N₂/CO, CO₂ and other common gas. According to partial pressure curves of H₂O, N₂/CO, CO₂ and the heating time, it could be judged that the temperature at that time was not high, which should be under 150°C.After thermal cleaning experiment of three GaAs photocathodes, it was found that the peak value of As partial pressure at low temperature was generally within 10^-11mbar~10^-10mbar, and the peak value was at 10^-10mbar at high temperature. Sometimes it was appeared that the peak value of As partial pressure at low temperature was even higher than the peak value at high temperature. The As volatilization phenomenon occurred at low temperature indicated that the elemental As exist on the GaAs photocathode surface or near surface after the chemical etching process, and the As could volatilize from GaAs photocathode at low temperature in the beginning of thermal cleaning. This research has guiding significance for further understanding the thermal cleaning mechanism of GaAs photocathode and improving the thermal cleaning technology.

Photocurrent of GaAs photocathode activated with Cs and O was tested by auto-activation monitor, the fitting curves of photocurrent showed that the photocurrent of the photocathode after the first activation declines exponentially, and then declines linearly with very small slope |k₁|; the photocurrent after the second activation rises exponentially, and then declines linearly with a slope|k₂| which is a bit larger than |k₁|.Based on the mechanism difference between twice annealing of the photocathode, the degeneration behavior of the photocathode was analyzed by three-dipoles model and XPS test after the first activation and succedent thermal cleaning. It is indicated that Cs₂O dipoles on the surface are saturated after the photocathode was activated for the first time, the remained Cs and Cs₂O in the ultra-high vacuum chamber which deposited on the photocathode surface will prevent the emission of photoelectrons. The photocathode surface with Cs and O reconstructed when it was annealing for the second time, a lot of Cs₂O dipoles changed into more stable GaAs-O-Cs dipoles, and this phenomenon would happened immediately as soon as the photocathode was activating for the second time. After the residual Cs and Cs₂O dipoles depleted, the neutral gas CO₂, H₂O, O₂, damaging the surface dipoles layer, are the main factors resulted in the decline of photocurrent. Due to the instable Cs₂O dipoles on the surface of photocathode have greater chances of converting into stable GaAs-O-Cs dipoles when photocathode was activated for the first time, the photocurrent declines more slowly compared with the second activation. The discussion for the phenomenon is of great significance for exploring the photoemission mechanism of Ⅲ-Ⅴ semiconductors.

In order to improve the electronic gain and luminance gain of low-light-level image intensifiers, microchannel plates(MCP) are adopted as the electron multiplier mechanism. According to the relevant experimental analysis, the resistance between channels is a limited value. Due to there are resistive coupling between any two adjacent channel of MCP, the electron transmission and the electron multiplication in a certain channel will be interfered by its adjacent channels, This phenomenon would affect the quality of image transmission and field of view of image intensifier. In low-light condition, the input current of MCP is small, the current gain of each channel is same, MCP has the area of linear current amplification and distortion-free image transmission. But when input current is large and close to saturation, lower current in channels has more current gain, leading to the contrast change of the image. This paper analyzes the transmission properties of electrons in the channels. It is proved that there is an electrical relationship between adjacent channels,throuht the circuit equations with relevant circuit parameters such as the resistance of secondary electron emission layer, resistance of resistive layer, the resistance between two adjacent channels, and so on. The analysis method and research results provide technical guidance for the improvement of electronic gain, luminance uniformity and preparation process of MCP.

This paper proposes an improved method of edge detection based on the mean shift algorithm. A pixel of an image calculated by the mean shift algorithm eventually converges to a peak point of probability density of the image. The pixel which is farther from the peak point has a greater mean shift vector and higher probability to be an edge pixel. The gradient of the mean shift vector of an edge pixel is a local maximum. During the mean shift iterations, the mean shift vector decreases by steps. Therefore, the vector of the first step is representative, while it is unnecessary to calculate each pixel to its convergence. This reduces the amount of computation and promotes the efficiency of the algorithm in a large extent. First, the image is smoothed by the mean shift filter, and the gradient of the mean shift vector is computed. Then, the local maximum is found by using non-maxima suppression on the gradient, which thins the edges detected. Finally, dual-threshold is used to detect and link edges. The edges detected have more accuracy and continuity. Experimental results show that the proposed method outperforms the conventional methods while suppressing noise and preserving edges.

The infrared characteristic simulation of the target is the basis of true and false infrared target recognition. With the development of stealth technology, imaging features of the decoy in the detector are more and more close to the real target, so it is not easy to distinguish between the target and decoy by using information acquired from single-band infrared detector. Based on this, in the paper infrared imaging properties of the target in a number of bands are simulated and analyzed, followed by fusing the characteristic differences of multiple bands between true and false target for classification and recognition. First of all, we construct the geometrical model of target and decoy in a simple background, and then the model of infrared radiation is built. What is more, in accordance with laws of infrared radiation and other relevant laws, the characteristics of target and decoy under the condition of different bands are analyzed. Experimental results show that the proposed multi-band target simulation and analysis method can effectively identify the target and decoy in the same field of view.

Vanadium oxide (VOx) thin films were prepared on unheated glass substrate by pulsed dc reactive magnetron sputtering using different pulse frequency. Field emission scanning electron microscopy (FESEM), x-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry (SE) measurements were made on the deposited VOx films to characterize the microstructure, composition and optical properties, respectively. It was found that under the same discharge power and argon-oxygen atmosphere, with the increase of pulse frequency, the vertical column-like structure in the films will gradually disappear and the ratio of high-valent VOx to low-valent VOx will obviously elevate. Optical parameters of the VOx films have been obtained by fitting the ellipsometric data (Ψ andΔ) using the Tauc-Lorentz dispersion relation and a multilayer model (air/roughness layer/VOx/glass). The results demonstrated that pulse frequency plays a critical role in determining the transmittance, refractive index, extinction coefficient and optical band gap etc. The correlations between the microstructure, composition, optical properties and pulse frequency are also given by our experiment results. And the mechanisms for the evolution of the microstructure, composition and optical properties with pulse frequency have been discussed. Overall, due to the pulse frequency had a great effect not only on the growth characteristics but also on the optical properties of the VOx films, thus through variation of the pulse frequency during deposition which provide a convenient and efficient approach to control and optimize the performances of the VOx films.

In our former research on YUV decomposition for color image recognition with joint transform correlator, the training images are displayed at the center position. However, the total side lobe energy may not be the minimum. In order to solve the problem, three components are rotated from -50° to 50° in steps of 2° and shifted from -3 to 3 pixels in both of vertical and the horizontal directions to yield shifted training images. 3 reference functions with lower side lobe energy on the output plane are yielded by using the method of minimum average cross correlation energy.

With the development of science and technology, CCD(Charge-coupled Device) has been widely applied in various fields and plays an important role in the modern sensing system, therefore researching a real-time image acquisition and display plan based on CCD device has great significance. This paper introduces an image data acquisition and display system of area array CCD based on FPGA. Several key technical challenges and problems of the system have also been analyzed and followed solutions put forward .The FPGA works as the core processing unit in the system that controls the integral time sequence .The ICX285AL area array CCD image sensor produced by SONY Corporation has been used in the system. The FPGA works to complete the driver of the area array CCD, then analog front end (AFE) processes the signal of the CCD image, including amplification, filtering, noise elimination, CDS correlation double sampling, etc. AD9945 produced by ADI Corporation to convert analog signal to digital signal. Developed Camera Link high-speed data transmission circuit, and completed the PC-end software design of the image acquisition, and realized the real-time display of images. The result through practical testing indicates that the system in the image acquisition and control is stable and reliable, and the indicators meet the actual project requirements.

Rb⁺, Cs⁺ and other alkali metal ions in the Micro-channel Plate（MCP）channel, under the action of an electric field, leave out of the channel wall of MCP, and accelerate to input surface of channel along the opposite direction of the electric field to form ion feedback-induced noise. The feedback ions will cause great harms, it will bombard the cathode surface, resulting in decreased cathode sensitivity, reducing tube life, so you must take measures to reduce ion feedback-induced noise. This paper analyzes how to reduce ion feedback-induced noise from five aspects of the MCP materials, etching, annealing in hydrogen, high-temperature baking and electron scrubbing. Through the utilization of mixed alkali effect of suppressing mutual diffusion and decreasing internal network cavity to improve structure of MCP glass wall, the diffusion coefficient of each ion is reduced; the content of Al₂O₃ is reduced to reduce the Na⁺, K⁺ diffusion losses; etching process is optimized, except for the acid corrosion, the alkali corrosion, special acid etching and vacuum baking process are used; annealing in hydrogen technology is also optimized, the time of annealing in hydrogen was chosen on 270 ~ 350 minutes; and the vacuum baking and electron scrubbing are handled before manufacturing. By the above methods the ion feedback-induced noise is reduced.

A novel multi-exposure images fusion method for dynamic scenes is proposed. The commonly used techniques for high dynamic range (HDR) imaging are based on the combination of multiple differently exposed images of the same scene. The drawback of these methods is that ghosting artifacts will be introduced into the final HDR image if the scene is not static. In this paper, a super-pixel grouping based method is proposed to detect the ghost in the image sequences. We introduce the zero mean normalized cross correlation (ZNCC) as a measure of similarity between a given exposure image and the reference. The calculation of ZNCC is implemented in super-pixel level, and the super-pixels which have low correlation with the reference are excluded by adjusting the weight maps for fusion. Without any prior information on camera response function or exposure settings, the proposed method generates low dynamic range (LDR) images which can be shown on conventional display devices directly with details preserving and ghost effects reduced. Experimental results show that the proposed method generates high quality images which have less ghost artifacts and provide a better visual quality than previous approaches.

In this paper, we present a method for single image blind deconvolution. Many common forms of blind deconvolution methods need to previously generate a salient image, while the paper presents a novel L0 sparse expression to directly solve the ill-positioned problem. It has no need to filter the blurred image as a restoration step and can use the gradient information as a fidelity term during optimization. The key to blind deconvolution problem is to estimate an accurate kernel. First, based on L2 sparse expression using gradient operator as a prior, the kernel can be estimated roughly and efficiently in the frequency domain. We adopt the multi-scale scheme which can estimate blur kernel from coarser level to finer level. After the estimation of this level’s kernel, L0 sparse representation is employed as the fidelity term during restoration. After derivation, L0 norm can be approximately converted to a sum term and L1 norm term which can be addressed by the Split-Bregman method. By using the estimated blur kernel and the TV deconvolution model, the final restoration image is obtained. Experimental results show that the proposed method is fast and can accurately reconstruct the kernel, especially when the blur is motion blur, defocus blur or the superposition of the two. The restored image is of higher quality than that of some of the art algorithms.

In this work, a modeling for reactive sputtering has been presented where the non-uniform current density is taken into account. The model in this paper can be used to understand the process of reactive magnetron sputtering. The results are compared with those that assume uniform discharge current density distributed on the target. It can be concluded that the process with the non-uniform discharge density shows a higher flow of gas reactive when occurring the hysteresis behavior. In addition, a study of the radial variation of the target composition in metallic and compound mode is also performed.

MgAl₂O₄ transparent phosphor ceramics were fabricated by hot-pressing and hot isostatic pressing using high-purity ultrafine MgAl₂O₄ powder mixed with phosphor. The microstructures of transparent phosphor ceramics were characterized by SEM and EDS. Moreover, the hardness and bending strength of transparent ceramics were measured. Effect of phosphor concentration (0~20%) on microstructure, hardness and bending flexture of transparent ceramics was analyzed. It was found that phosphor doping plays an important role in improving the mechanical property of transparent ceramics. So applying this kind of transparent phosphor ceramic to LED components as packaging material can significantly improve the lifetime and reliability of LED products.

Low-impedance long-wave infrared detectors (the wavelength longer than 10 microns) have very important applications in cryogenic aim detection, super-distance detection, anti-jamming target identify and so on. Therefore the research in the field of infrared detector technology is of importance. At present, no low-impedance photoconductive detectors are integrated with CMOS circuit. To design low-temperature CMOS circuit being fit for low impedance infrared photoconductive detector and realize high performance IR imaging, using differential amplifier with symmetrical positive and negative power is necessary, the low-resist detector is connected between an input and grounding, the corresponding low resistance is connected between another input and grounding, a larger feedback resistor is used between negative input and output, this structure can effectively solve the matching problem of low-impedance and high-impedance CMOS. In addition, the noise voltage from VBIAS terminal can be effectively reduced by increasing the ratio of the bias resistor and the detector resistance. The whole circuit is designed two grade. The first grade is adopted bridge input structure, this structure is fit for low impedance detector. The positive amplifying method is applied in second grade . The first grade feedback resistance is designed 1M ohm, the circuit is supplied by ±1.5V. The testing showed that the circuit can work well when it connects with low-impedance infrared photoconductive detector at the liquid nitrogen low temperature. The magnification is up to 30000 times, 3dB bandwidth is more than 4kHz, the equivalent input noise is near 1.5 micron volts. This circuit has perfectly solved the matching problem between high impedance CMOS circuit and low impedance detector.

The metamaterial absorber in terahertz (THz) region, with the metal pattern layer/dielectric spacer/metal reflective layer sandwich structure, is characterized in this paper. The principle of metamaterial absorber absorbing terahertz wave was introduced firstly. The top layer of metamaterial absorber is a periodically patterned with metallic subwavelength structure, which also serves as an electric resonator. The bottom layer is a thick metal plane, which is used to reduce THz wave transmittance. The dielectric layer between two metallic layers results in magnetic resonance and the resonance depends on the thickness and dielectric constant of the dielectric layer. The absorption of metamaterial absorber to terahertz wave was simulated with CST software. The relationship between the size of the metamaterial structure and absorption frequency was analyzed with the simulation results. The results indicate that the absorption frequency is affected by the cell constant and geometric structure of top metal pattern, and absorption rate is related to both the thickness of dielectric layer and the size of resonator. In the end, the possibility of integrating the metamaterial absorber with micro-bridge structure to design room temperature terahertz detector was discussed, and the manufacturing process was introduced about room temperature terahertz detector with high THz wave absorption rate.

Poly(vinylidene fluoride) (PVDF) is a semi-crystalline polymer, which indicates four different crystalline forms. In this paper, the preparation of nanoscale PVDF thin film was introduced in detail. Initially PVDF was dissolved in the N,N-dimethyl Formamide and acetone mixed solution (volume ratio 1:1). The PVDF films were prepared by spin coating method with different solution concentration, then were characterized by SEM, XRD and FTIR after annealed at different annealing temperatures (60 centigrade to 120 centigrade). Due to the formation of polarized β crystal phase in the annealing process, the pyroelectric coefficient p would be affected by different annealing temperatures. The thermal poling technique of PVDF was also shown in this paper. We investigated the polarization behavior of PVDF when they were subjected to different poling electric fields (from 50 V/μm to 80 V/μm) and poling temperatures (from 90 centigrade to 120 centigrade). For a long enough poling time, the polarization is only related to poling electric filed, while poling temperature affects the poling rate merely. Under the condition of PVDF thin film beforet breakdown, the strongger the poling electric filed intensity, the higher the pyroelectric coefficient is. The pyroelectric coefficient of fibricated PVDF film is 9.0×10^-10C/cm²K after 80v/μm electric field intensity polarization from experiment result.

Using the projected augmented wave potential by the density functional theory based upon gradual gradient approach method and the slab model, from the calculated surface, we identify the relaxed atoms sites of GaAs(110) surface, the electronic structure of elements K and O adsorpted on binding sites of ideal GaAs(110) surface have also been calculated, especially the total energy of the adsorption system. The comparison results of calculated total energy showed: for K and O elements at highest coverage of Θ=1ML on GaAs(110) surface, they were not formed to local domain of competitive chemical adsorption, while they were formed to a compound uniformity phase of cooperative chemical adsorption. Our calculated results providing theoretical basis and reference for the application of alkali oxidation adsorpted on GaAs surface to form a negative electron affinity photocathode.

The applied field can cause the inversion symmetry of the silicon single crystal is destroyed and disappears. So the silicon produce a second-order nonlinear optical effect. We exhibition electro-optic effect with index ellipsoid method for analyzing along different direction applied electric field. The result can be used to designing silicon electro-optic modulation.

To overcome the difficulty in segmenting moving objects from a video sequence taken by a freely moving camera, we propose a new segmentation cue based on a joint spatial-color representation for the foreground and background appearances. Given the segmentation result in the previous frame, two sample sets can be extracted for foreground and background, respectively. We transform the spatial locations of the samples in the two sets towards the current frame, then use these transformed samples to evaluate the foreground and background likelihood maps, and combine these maps to form a likelihood ratio map which is further exploited as a segmentation cue and integrated into a conditional random field energy function. The total conditional random field energy is minimized by the graph cut, leading to a binary mask of moving objects for each video frame. We validate the proposed segmentation cue using several video sequences taken by hand-held cameras in outdoor urban scenes and the results show the effiency of the segmentation cue.