Abstract:

Abstract:采用气态源分子束外延方法及应用有源区同质结构及较薄的组分渐变InxGa1-xAs缓冲层，研制了波长扩展的InGaAs／InP光伏探测器系列，其室温下的截止波长分别约为1．9μm，2，2μm．和2．5μm．对此探测器系列在较宽温度范围内的性能进行了细致表征，结果表明在室温下其R0A乘积分别为765，10．3和12．7Ωcm^2，比室温降低100K时其暗电流和R0A可改善约3个量级．瞬态特性测量表明此探测器系列适合高速工作，实测响应速度已达数十ps量级．

Abstract:A newly developed near-infrared optical mammographer based on frequency-domain techniques was presented. In comparison with our former prototype with multiple sources and detectors, the new one used single source and detector. This structure not only eliminates the matching issues between the channels but also simplifies the system and reduces the cost. The results of intralipid and clinical experiments have proved that the system has high sensitivity and resolution, which indicates its promising potential to serve as a proficient method of breast cancer detection.

Abstract:According to the short integration time characteristics of long wave infra-red focal plane array, the principle and application of oversample-superpositon technique were discussed. The effect of oversample-superpositon on the MTF of system was analyzed on the basis of the chareaeteristics of LWIR FPA. The corresponding oversample-superpositon MTFs at different sampling and superpositon time were given. As the superposion time deereases, the detector MTF is reducing while system scanning MTF ix rising when the sampling time is fixed.

Abstract:The resonant transmission properties of a photonic quantum-well were studied by a spheric-wave expansion method in combination with multiple-scattering techniques. Similar to the electronic quantum wells the photonic quantum-well is constructed by sandwiching a uniform medium between two photonic barriers. The calculated resonant transmission peaks show that some photonic states exist in a quantized way, satisfying a quantized frequency relation. The finite photonic potential barrier plays different confining roles on the different photonic levels. By appropriately choosing the parameters of the well and barrier, a high-quality multichannel filtering can be achieved. The calculation in the coupled double photonic quantum-wells shows that the coupling between the modes in the two wells weakens with the widening of the barrier thickness, and the mode splitting becomes smaller.

Abstract:Progress in Hybrid Uncooled Pyroelectric IR FPA was introduced. Not only the electric and physical characteristics of the materials that are used in the FPA,but also its heat isolation structure and ROIC technology were discussed in datail.The key factor of the FPA's performance was analyzed.At last,the experimental result and some methods were discussed and analyzed.

Abstract:For researching millimeter wave power combining technique, a new style low loss millimeter wave microstrip integrated 3dB hybrid, extracting advantages from traditional Wilkinson hybrid, was proposed. It is easily fabricated and with low cost, and its insert loss is about 0.2dB in 32GHz - 37GHz. Based on this new style 3dB hybrid, a Ka-band power combining network was presented, and in 33 - 35GHz frequency band, the combining efficiency about 75% was obtained.

Abstract:Not only spatial noise but also spectral noise exists in hyperspectral images.Only spatial noise but no spectral noise is removed with traditional image filters.To improve this situation DSGF(Derivative based Savitzky-Golay Filter) method was presented here.First noise level of each especial band is determined based on the second derivative of reflectance,then reflectance is filtered twice by Savitzky-Golay filter sizes,which results in removing spectral noise in hyperspectral image.In the meanwhile most fine features of reflectance are remained after hyperspectral image is filtered pixel by pixel by DSGF filter.

Abstract:在可靠性筛选中检测具有潜在损伤的器件一直是个难题。对GaAlAs红外发光二极管（IRLED）功率老化前后低频噪声的测量发现，1／f噪声幅值与偏置电流的γ次方成正比（小电流区γ≈1，在大电流区γ≈2），且老化后1／f噪声幅值比老化前增大2个数量级。基于载流子数涨落和迁移率涨落机制建立了一个GaAlAs IR LED的1／f噪声模型，分析结果表明GaAlAs IR LED的1／f噪声在小电流时反映体陷阱特征，大电流时反映激活区陷阱特征，l／f噪声的增加归因于功率老化诱生的界面陷阱和表面陷阱，1／f噪声可以用来检测GaAlAs IR LEDs的潜在缺陷/

Abstract:In order to simulate the radiance of infrared and water vapor channels of FY2B with RTTOV, a multi-variables linear regression was used to produce transmittances by using spectral response functions of these channels and a precise transmittances database of 600 - 3000 cm^ - 1 generated from GENLN2 at 6 viewing angles. When the same atmospheric profile and the new coefficients were put into RTTOV, simulation of FY2B and GMS showed that similar channel radiances were obtained. The comparative analysis of the deviation between the simulated radiances obtained with the profiles from ECMWF model forecast and the new coefficients for FY2B in RTTOV and the real observation for infrared and water vapor channels of FY2B indicate that the satisfying precise of radiances can be obtained within very short time.

Abstract:The adaptive Butterworth high pass filter(BHPF) is an effective method for detecting infrared small targets under sea-sky complex backgrounds.However,false alarms will inevitably exist when this approach is used to detect infrared video sequences images.Through estimating the local energy difference of small target regions in the filter images,which is directly caused by the different cutoff frequencies of BHPFs in consecutive two frames,an adaptive method for conducting the detection threshold of small targets in the filtered images was proposed here.Experimental results confirm that our algorithm can not only solve the problem of false alarms mentioned above,but also is effectively adapted to the conditions that the target is temporarily lost or the backgrounds are suddenly changed.

Abstract:A micro-cantilever uncooled infrared(IR) detector was designed and fabricated based on standard silicon process.Because silicon nitride(S_iN_x) and aluminum(Al) have different thermal expansion coefficients,bi-material micro-cantilever that is composed of the films of S_iN_x and Al will bend when it absorbs IR radiation and its temperature changes.The variable micro-capacitor between the micro-cantilever and the substrate will change as the micro-cantilever bends.Hence,the information of IR radiation can be known when the change of the variable micro-capacitor is detected.The test of a single detector by outer apparatus shows that the micro-cantilever has strong response to IR radiation.

Abstract:The operation mechanism of high frame rate frame-transfer CCD array was analyzed. Driver circuits and signal processing circuits were designed. The image with high visibility was acquired by the CCD working on 130 fps. A new method to improve the frame rates was presented. The method introduces a light-proof board, and it has higher ratio of effective exposure, thus the frame rate is raised up to 400fps. Hence, the quality of the image is improved.

Abstract:从用傅里叶变换红外光谱仪（FTIR）测量室内高温气体的红外发射光谱出发，对气体辐射源的几何参数进行了优化设计，讨论了辐射源的几何参数——R、f、H的范围，指出了获得高温气体不连续发射光谱和连续发射光谱的条件；对高温气体的辐射特性进行了研究。

Abstract:Two kinds of continuous structure bandstop and lowpass microstrip filters named 'uniform' and 'constant ratio' were studied by matrix multiplication method.The effect of structure parameters on the filtering property was analyzed.The filters were fabricated and measured.And the theoretical results are basically in agreement with the experimental results.

Abstract:An improved experimental device based on the wavelength scanning method was developed to measure the polarization mode dispersion of polarization maintaining fiber. The algorithm of density of extrema was used to calculate the polarization mode dispersion of fiber. A method to reduce the affection of the noise was applied and the accuracy of the measurement was improved.

Abstract:Based on the mode coupling theory, the design of TE01-TM11 mode converter geometry configuration with traditional waveguide axis constant curvature and improved waveguide axis sinusoidal curvature Was presented for more acceptable geometry parameters. More considerations were given to the influences of muhimode factor, backward wave, ohmic losses carried from metal wall and phase rematch. The conversion efficiency of Ka waveband with waveguide axis sinusoidal curvature is about 99% with bandwidth of 32%. At the same time, the relation among the radius and curvature of circular waveguides, the length of converter and converting efficiency is obtained.

Abstract:According to the deficiency of temperature and emissivity separation(TES) model,a modified method of TES was presented.Simulated data were used to compare the precision of temperature and emissivity retrieved separately from before and after model modification.The sensitivity of TES and MTES model to the variety of initial setted emissivity,calibration error of atmospheric upwelling,downwelling radiation and transmission was then analyzed by way of theoretically analysis and simulated computation.Results show that the retrieval precision of MTES model is higher than that of TES model.Except for the calibration error of atmospheric downwelling radiation,other errors affect the precision of the two models,but MTES model is less sensitive to these errors.

Abstract:The signal process of a laser seeker was analysed on time domain when it was interfered by a laser cheating jammer. A laser guidance System with countermeasure acting as an interfered target and a laser cheating jammer acting as an interfering source,the interactional effect between them was tested from the view of systems on field. The angle errors between the sight of target and the optical axial of a laser seeker were used to characterize the interactional effect. The results show that the effect of a laser cheating jammer on a laser seeker closely relates to the output power of the jammer and the performance of the cheating signal and environmental elements and the methods of signal processing of a laser seeker.