Abstract:Perfect electromagnetic wave absorber is generally called perfect absorber for short. It can be used in many industries. A perfect absorber which can operate in Near Infrared (NIR) band is studied by finite-different time domain method. The simulation result shows that this perfect absorber can achieve 98% absorbance for a single peak at the wavelength of 1400 nm or more than 90% absorbance for two peaks at the wavelengths of 1320 nm and 1640 nm. The absorption wavelength and absorption width can be tuned by adjusting the resonance cavity structure of the absorber. The perfect electromagnetic wave absorber is a perfect absorber with a back-to-back resonance cavity, which has a very wide application prospect.

Abstract:For a precise angle measurement positioning system, the existence of distortion may affect the geometric measurement accuracy directly. Therefore, the distortion of the optical system should be calibrated for its subsequent distortion correction. To solve the distortion calibration problem of a F-Theta optical lens, a calibration system based on the precise angle measurement method is established. The distortion calibration process is discussed in detail. The relation between the field of view and the absolute distortion is measured experimentally. The focal length of the F-Theta optical lens is derived by the least square approximation method based on curve fitting. Finally, the angle measurement accuracy of the F-Theta optical lens is analyzed. The result shows that the lens can meet the requirement of second-level angle measurement accuracy.

Abstract:In combination with the advantages of classical variational assimilation and regularization constraint, a multi-parameter regularization constraint assimilation method is studied. Unlike the weight of background and observation to the objective functional of classical variational assimilation, the regularization constraint can adjust the weight of observation term and give the weight function on the basis of Huber-estimator weight function during regularization parameter optimization. Simulation brightness temperature experiment is made for the water vapor channel of the Hyper-spectral Atmospheric Infrared Sounder (AIRS). The result shows that the variation method studied is better than the classical variational assimilation method. The influence of observation data on analysis fields is diagnosed on the basis of the degree of freedom for signals. The result shows that the method studied can effectively extract the brightness temperature information from the water channel of AIRS.

Abstract:The surface damage in both wire-electrode cutting InSb wafers and inside-diameter cutting (ID-cutting) InSb wafers was studied by means of Scanning Electron Microscopy (SEM), profilometer and X-ray diffraction (XRD). The thickness of the damage in InSb wafers was analyzed quantitatively. The factors that have influences on the surface damage in cutting InSb wafers were discussed. The results showed that the wire-electrode cutting InSb wafers had smooth surfaces, small roughness and small surface damage. The thickness of the damage layers in wire-electrode cutting InSb wafers was about 14 μm which was less than that of the ID-cutting InSb wafers. This research result was of referential value to the mass production and subsequent processing of large-size InSb wafers.

Abstract:As an excellent light absorption semiconductor material, organic-inorganic hybrid halide perovskite has been widely used in the field of optoelectronics. To fabricate high performance photoelectric detection devices, a highly ordered ultra-long CH3NH3PbI3 nanowire is prepared by solution process and is used to fabricate an Au/CH3NH3PbI3/Au planar photoelectric detector. The device has a wide operation waveband. It has light response in the spectral range from ultraviolet to near-infrared (365-808 nm). Its maximum light responsibility (R), detectivity (D*), Ilight-Idark ratio and light response time are up to 3.81 A·W-1, 3.7×1011 Jones, 4.9×103 and 7 ms respectively. Because of excellent light detection ability, the device has a wide application prospect.

Abstract:The influence factors of pulse infrared heat wave detection technology were studied through ANSYS finite element simulation and experiment. Taking glass fiber reinforced plastics, carbon fiber and thermal barrier coating as examples, simulation was carried out. The influences of environment and material defects on pulse infrared thermal wave detection were studied mainly. The ability of the detection technology for glass fiber reinforced plastics and carbon fiber was determined. Test was carried out for carbon fiber and glass fiber reinforced plastics. The influence of experiment condition on detection was studied. The optimum experimental parameters for glass fiber reinforced plastics and carbon fiber were also given.

Abstract:Shaft runout has an important influence on the machining performance of machine tools. To meet the requirements of high precision, real-time and on-line shaft runout measurement, a novel efficient laser coherence technique for shaft runout measurement is proposed. Because of the use of a stable and reliable He-Ne laser based on Zeeman effect as the light source, the technique has the advantages of high sensitivity, high signal-to-noise ratio, high accuracy and long detection range. In addition, with the transmission by optical fiber, the flexibility and anti-interference of measurement are further improved. The demand of real-time and online long range measurement can be satisfied. The experimental result shows that the measurement uncertainty of this system is less than 0.1%.

Abstract:As an important equipment for semiconductor production, Rapid Thermal Annealing (RTA) needs precise and reliable temperature control. Usually, it uses a pyrometer to measure its temperature. In the use of the pyrometer, because of many reasons, the temperature of the pyrometer should be calibrated. On the basis of a certain imported rapid thermal annealing furnace, the temperature calibration method of its pyrometer is analyzed. Both thermocouple and melting-point sampling methods are presented and are used to enrich the sampling data for temperature calibration. The temperature calibration data in the range from 1000℃ to 1500℃ are estimated by linear calculation. Through the data sampling based on curve fitting, more accurate temperature calibration results are obtained. The advantages and disadvantages of both temperature calibration methods are analyzed by comparison. The result shows that the linear calculation temperature calibration method is more suitable for the temperature calibration below 1100℃ and the curve fitting temperature calibration method is more suitable for the temperature calibration above 1100℃.

Abstract:With the progress of science and technology, society is evolving toward intelligence. To use real-time paper literature monitoring to realize the preservation of paper literature will be an inevitable development trend in the future. In order to provide the basis for the real-time monitoring of library literature, Fourier transform medium infrared photo-acoustic spectroscopy is used to determine the water content in paper in combination with stoichiometry. A quantitative model of paper water content is established by Principal Component Regression (PCR) and Partial Least Squares Regression (PLSR) respectively on the basis of medium-infrared photoacoustic spectroscopy. The optimum primary component number is selected by cross-validation. The result shows that the modeling result of partial least squares regression is better than that of the principal component regression (the determination coefficient is 0.3681>0.3532). By increasing the number of principal component, the prediction of the models will be better. However, there are some risks of fitting. In the future, more paper samples will be collected so as to establish a stable paper quality detection model and lay a basis for the real-time infrared spectrum monitoring of paper literature.