激光水下偏振特性用于目标图像探测

利用激光水下偏振特性获得偏振差分图像(PDI),并运用PDI技术,从理论和实验上对水下目标探测进行了研究.介绍了PDI基本概念和实验系统原理,然后比较分析了不同条件下普通图像与PDI在辨别目标距离及其纹理上的差别和PDI中背景偏振光的影响,得出利用目标和背景偏振光的差异区分二者,从而提高探测距离的结论,并取得了较好的效果.在此基础上提出了通过处理有关PDI偏振参量来进一步辨别目标与背景的设想.     

Room temperature diluted magnetic semiconductor synthesized by dual beam laser deposition

Diluted magnetic semiconductor Co-doped ZnO film has been synthesized by a dual beam pulsed laser deposition method. The magnetic, electrical, and optical properties of the Zn_0.985Co_0.015O_0.67 film are studied in this paper. The film shows ferromagnetic behavior with a coercivity of about 300 Oe at room temperature, and semiconductor behavior with carrier concentration of 2.2×10¹⁸ cm^-3, and a resistivity of 102 mcm. Structural investigations indicated that the film has similar lattice constants to that of ZnO. It is shown that the film exhibits excellent optical properties with a band gap energy of 3.31 eV, which is close to that of ZnO. The origins of the magnetism are also discussed. PACS 81.15.Fg; 75.50 Pp; 61.72.Vv     

CN红带A^2Πi-X^2Σ^＋（6，1）和（7，2）带振转光谱研究

通过微量CH3CN(36Pa)与He(660Pa)混合气体交流Penning辉光放电获得CN自由基分子，采用光外差-磁旋转-浓度调制光谱技术，在可见光波段16850～17480cm^-1进行了转动分辨光谱测量，分别标识了CN分子红带A^2Πi-X^2Σ^ (6，1)和(7，2)138条和118条的转动光谱(其余光谱为C2自由基及CN红带(8，3)带光谱)。理论拟合分子常数时考虑电子态间的微扰作用，采用有效哈密顿量矩阵对角化获得了A^2Πi(v=6，7)态更精确的分子常数及电子态A^2Πi(v=7)与X^2Σ^ (v=11)之间的微扰常数ξ，η，总体拟合方差均小于实验误差0．007cm^-1，表明拟合结果是非常精确的。     

Saturation field direction dependence of domain structures in NiFe elements

The domain structures in NiFe elements were studied by magnetic force microscopy measurement and micromagnetic modeling. The remanent states in the elements were dependent on the direction of the saturation field. The “S” and “U” states were observed at remanence by applying the saturation field at different directions. The “S” and “U” states are metastable: magnetic force microscopy tip field-induced switching from the “S” and “U” states to the flux closure configuration was observed.     

光纤白光干涉仪等臂长技术研究

介绍了几种光纤干涉仪等臂长技术,比较了各自的优缺点和适用范围,对光纤干涉仪的平衡有较大的参考价值。     

皮肤晚期糖基化终末产物的自体荧光光谱特性

在分析晚期糖基化终末产物(Advanced glycation end products,AGEs)标准品三维荧光光谱和皮肤中AGEs自体荧光光谱的基础上,确定了皮肤中AGEs的最佳激发波长为370 nm.使用自行设计的皮肤荧光光谱检测装置对正常人和糖尿病患者皮肤AGEs的荧光光谱进行了检测,结果表明:在418,450...     

自由基型光引发剂的瞬态及稳态荧光特性研究

利用荧光光谱技术研究了不同自由基型光引发剂的瞬态及稳态荧光光谱特性,从分子结构出发分析了共轭结构对光引发剂荧光光谱的影响.实验结果表明随共轭效应的增强,荧光激发与发射峰波长逐渐增大;瞬态荧光谱的衰减受电子基团的影响较为明显,含有吸电子基团的光引发剂荧光衰减快,而含有给电子基团的光引发剂荧光衰减慢.通过对溶剂极性及粘度研...     

应变Si/(001)Si1-xGex电子迁移率

依据离化杂质散射、声学声子散射和谷间散射的散射模型,在考虑电子谷间占有率的基础上,通过求解玻尔兹曼方程计算了不同锗组分下,不同杂质浓度时应变Si/(001)Si_1-xGe_x的电子迁移率.结果表明:当锗组分达到0.2时,电子几乎全部占据Δ₂能谷;低掺杂时,锗组分为0.4的应变Si电子迁移率与体硅相比增加约64%;对于张应变Si NMOS器件,从电子迁移率角度来考虑不适合做垂直沟道.选择相应的参数,该方 关键词： 电子谷间占有率 散射模型 锗组分 电子迁移率     

Colorless gigabit WDM-PON link using injection locking and electro-absorption transceiver

In this paper, a novel colorless wavelength division multiplexing-passive optical network (WDM-PON) system using injection locking and electro-absorption transceiver (EAT) is proposed and demonstrated experimentally. This system has advantages, high data transmission, small downlink signal effect to uplink signal and less polarization sensitivity, compared to the system using reflective semiconductor optical amplifier (RSOA). Downlink signal modulates the right side carrier of the double side band signal by using injection locking. EAT functions as both photo detector in downlink signal and modulator for uplink signal, simultaneously. A possible cross absorption modulation effect from the EAT is analyzed experimentally. Bidirectional transmission of 1.25 Gbps and 622 Mbps for downlink and uplink, respectively, were verified through 23 km standard single mode fiber (SSMF).