由于生产工艺灰尘、坏像素等多种因素都会造成CMOS像元辐射响应特性不一致, 影响成像系统的图像质量, 因此, 能够高效快速地测出异常像素的位置和大小是图像处理过程中必要的预处理技术。通过实验分析了固体成像器件像元的响应特性, 提出了一种基于K-Means算法的CMOS像元响应特性分类方法, 该方法根据像元像素值存在的差异, 不仅能够有效地检测出异常像元, 而且可以对异常像元进行分类。实验表明, 该方法能有效地检测出CMOS器件中异常像元的位置, 和异常像元区域大小与传统的”3[σ]”算法相比, 该方法对异常像元区域查找速度快, 定位准确。

We propose a novel structure and unique sensing mechanism bio-chemical sensor which is fabricated by a polymer long-period waveguide grating with the detection liquid directly as the waveguide cladding. Quantitative detection is realized from analyzing the output absorption spectrum and resonant wavelength shift related to the liquid detection concentration. The proposed polymer long-period waveguide grating based liquid refractive-index sensor is developed experimentally, the high sensitivity of 1.01 × 10⁴ nm/RIU is achieved, and the temperature stability coefficient is 1.47 nm/℃. Theoretically and experimentally, this work has been demonstrated to have potential application in chemical and biological detections and may provide an important technical support for solving today’s increasingly serious civil problems such as food safety and drug safety, which will also have the important scientific significance and application prospects.

This paper presents a new technique for flat optical frequency comb (OFC) generation, which is based on the nonlinear process of multiple four-wave mixing (FWM) effects. The nonlinear effects are significantly enhanced by using the proposed optical feedback scheme consisting of a single mode fiber (SMF), two highly nonlinear fibers (HNLFs) with different zero dispersion wavelengths (ZDWs) and polarization beam splitters (PBSs). Simulation results illustrate its efficiency and applicability of expanding a comb to 128 coherent lines spaced by only 20 GHz within 6-dB power deviation.

提出了一种基于标记栈技术的两跳相干探测光谱幅度码（SAC）标记交换系统。利用仿真软件，搭建了包含两个转发节点、两个156 Mb/s光谱幅度码标记、与40Gb/s差分正交相移键控（DQPSK）净荷的光标记交换系统。利用接收光功率与光信噪比（OSNR）分析系统传输性能，并得到结论：经两个节点传输后，标记与净荷产生的功率代价与OSNR代价均未超过3 dB。

提出一种用于强电场测量的集成光波导电场传感器天线电极设计方案。给出了传感器等效电路, 计算分析了天线、电极的各个参数对传感器半波电场的影响。结果表明: 当传感器电极长度、天线长度由4mm减少到0.5mm时, 传感器半波电场由230kV/m分别增加到2400kV/m和1100kV/m, 提高了943.5%和378.3%;当电极间距、电极宽度由20μm增加到200μm时, 传感器半波电场由400kV/m分别增加为2300kV/m和730kV/m, 提高了475.0%和82.5%;当天线底部宽度由50μm增加到600μm时, 传感器半波电场由460kV/m减小到242kV/m, 减小了47.4%。因此, 合理设计传感器电极、天线尺寸可使其半波电场达到几百kV/m至几千kV/m, 使它能够应用于强电场测量领域。

首先介绍了级联结构光纤参量放大器的工作原理, 即通过两种光纤色散补偿来平坦信号输出增益。其次推导出小信号近似下单泵浦级联光纤参量放大器的信号输出增益表达式, 并在此基础上利用Matlab软件对影响增益特性的各个参数进行数值分析。结果表明, 级联光纤参量放大器的峰值增益与增益带宽, 受到分段数、泵浦光功率、泵浦波长、色散补偿光纤(DCF)长度、高非线性光纤(HNLF)的零色散波长、HNLF长度、HNLF非线性系数和HNLF色散斜率的影响。

A Lithium niobate (LiNbO3) based integrated optical E-field sensor with an optical waveguide Mach-Zehnder interferometer (MZI) and a tapered antenna has been designed and fabricated for the measurement of the pulsed electric field. The minimum detectable E-field of the sensor was 10 kV/m. The sensor showed a good linear characteristic while the input E-fields varied from 10 kV/m to 370 kV/m. Furthermore, the maximum detectable E-field of the sensor, which could be calculated from the sensor input/output characteristic, was approximately equal to 1000 kV/m. All these results suggest that such sensor can be used for the measurement of the lighting impulse electric field.

设计了马赫-曾德尔(MZ)调制器工作点控制的前端电路。利用运放OP27设计文氏桥电路, 产生1kHz余弦波, 作为扰动信号加到MZ调制器的RF端。运用运放OP27设计带通滤波器, 从探测器分别提取一次谐波和二次谐波。利用乘法器MLT04实现对一次谐波和二次谐波的检波, 分别得到一次谐波的幅度调制信号和二次谐波的幅度调制信号。这两个调制信号含有调制器工作点的相位信息, 为后续的软件控制提供了两路含有相位信息的信号, 使整个控制系统的实现更准确。

介绍了时域有限差分(FDTD)法的理论与基本原理。利用该方法，得到了可对集成光波导偶极子电场传感器幅频特性进行理论分析的数学表达式。为优化器件性能，利用仿真，对在低频与高频电磁波入射时，不同电极长度/宽度下的器件幅频特性进行了比较。结果表明，低频电磁波入射时，采用较长或较窄的电极，均可提高器件的响应幅度；改变电极长度与宽度，对器件响应频率几乎没有影响。高频电磁波入射时，采用较长或较窄的电极，器件同样可获得较大的响应幅度；改变电极宽度，对器件响应频率的影响很小，但较长的电极会显著降低器件的响应频率。