双折射光纤中偏振模色散的抑制

利用双折射光纤中孤子自捕获现象可以抑制偏振模色散,但这种抑制技术对传输参量有严格的限制.本文提出在双折射光纤中周期性地改变快慢轴的方法来抑制偏振模色散. 研究发现,这种方法在一定程度上能有效地抑制偏振模色散,并且光纤间偏振轴的夹角偏差有利于对偏振模色散的进一步抑制.     

The （l＋l）-dimensional spatial solitons in media with weak nonlinear nonlocality

We study the propagation of (1+1)-dimensional spatial soliton in a nonlocal Kerr-type medium with weak nonlocality. First, we show that an equation for describing the soliton propagation in weak nonlocality is a nonlinear Schr?dinger equation with perturbation terms. Then, an approximate analytical solution of the equation is found by the perturbation method. We also find some interesting properties of the intensity profiles of the soliton.     

A novel technique for predicting ionizing radiation effects of commercial MOS devices

A nondestructive selection technique for predicting ionizing radiation effects of commercial metal-oxide-semiconductor (MOS) devices has been put forward. The basic principle and application details of this technique have been discussed. Practical application for the 54HC04 and 54HC08 circuits has shown that the predicted radiation-sensitive parameters such as threshold voltage, static power supply current and radiation failure total dose are consistent with the experimental results obtained only by measuring original electrical parameters. It is important and necessary to choose suitable information parameters. This novel technique can be used for initial radiation selection of some commercial MOS devices.     

Optical Beams in Media with Spatial Dispersion

We theoretically predict a novel phenomenon of the diffraction-free propagation of the paraxial optical beam in the isotropic or cubic linear medium with spatial dispersion.Under the weak spatial dispersion condition,the paraxial wave equation is derived,in which there is the diffraction term with the coefficient Γ that depends on the compensation between the classic diffraction and spatial dispersion.Near the exction dipole absorption line,we can have Γ=0,then the beam propagates diffraction-freely,and its shape keeps unchangeable.Discussed are also the physical mechanism and the possible experimental candidates of crystals for the phenomenon.     

激光诱导扩散区的温度监控

激光诱导扩散中的曝光区大小为１０μｍ量级，其温度分布的测量是较困难的。本文报道一我中极微小面积的不接触及控制。文中介绍测控原理、实验装置，给出测量结果。     

质子辐照导致科学级电荷耦合器件电离效应和位移效应分析

针对卫星轨道上的空间环境辐射引起电子元器件参数退化问题, 为了研究光电器件空间辐射效应、损伤机理以及参数退化规律, 对某国产埋沟科学级电荷耦合器件(charge-coupled devices, CCD)进行了10 MeV质子辐照试验、退火试验及辐射效应理论模型研究. 试验过程中重点考察了器件的暗信号和电荷转移效率特性的变化. 试验结果表明, 器件的主要性能参数随着质子辐照注量的增大明显退化, 在退火过程中这些参数均有不同程度的恢复. 通过对CCD敏感参数退化规律及其与器件工艺、结构的相关性进行分析, 并根据半导体器件辐射效应理论, 推导了器件敏感参数随质子辐照注量变化的理论模型, 得到了暗信号及电荷转移效率随辐照注量退化的半经验公式. 上述工作可为深入开展CCD抗辐射性能预测、抗辐射工艺改进与结构优化提供重要参考.     

质子与中子辐照对电荷耦合器件暗信号参数的影响及其效应分析

对科学级电荷耦合器件(charge-coupled device, CCD)进行了质子和中子辐照试验及退火试验, 应用蒙特卡洛方法计算了质子和中子在CCD中的能量沉积, 分析了器件的辐射损伤机理. 仿真计算了N⁺埋层内沉积的位移损伤剂量, 辐照与退火试验过程中主要考察暗信号的变化规律. 研究结果显示, 质子与中子辐照均会引发暗信号退化, 其退化的规律与位移损伤剂量变化一致; 退火后, 质子辐照所致CCD暗信号大幅度恢复, 其体暗信号增加量占总暗信号增加量的比例最多为22%; 中子辐照引发的暗信号增长主要为体暗信号. 质子和中子在N⁺埋层产生相同位移损伤剂量的情况下, 两者导致的体暗信号增长量相同, 质子与中子辐照产生的体缺陷对体暗信号增长的贡献是同质的.     

锗硅异质结双极晶体管单粒子效应加固设计与仿真

本文设计了一种通过在版图布局中引入伪集电极的方法来提高锗硅异质结双极晶体管(SiGe HBT)抗单粒子性能的方法. 利用半导体器件模拟工具, 针对加固前后的SiGe HBT开展了单粒子效应仿真模拟, 分析了伪集电极对SiGe HBT电荷收集机理的影响. 结果表明, 引入的伪集电极形成的新的集电极-衬底结具有较大的反偏能力, 加固后SiGe HBT伪集电极通过扩散机理, 大量收集单粒子效应产生的电荷, 有效地减少了实际集电极的电荷收集量, 发射极、基极电荷收集量也有不同程度的降低, 加固设计后SiGe HBT 的单粒子效应敏感区域缩小, 有效的提高了SiGe HBT 器件抗单粒子效应辐射性能. 此项工作的开展为SiGe HBT电路级单粒子效应抗辐射加固设计打下良好的基础.     

CMOS有源像素传感器的中子辐照位移损伤效应

为研究空间高能粒子位移损伤效应引起的星用CMOS图像传感器性能退化,对国产CMOS有源像素传感器进行了中子辐照试验,当辐射注量达到预定注量点时,采用离线的测试方法,定量测试了器件的暗信号、暗信号非均匀性、饱和输出电压、像素单元输出电压等参数的变化规律。通过对CMOS图像传感器敏感参数退化规律及其与器件工艺、结构的相关性进行分析,并根据半导体器件辐射效应理论,深入研究了器件参数退化机理。试验结果表明,暗信号和暗信号非均匀性随着中子辐照注量的增大而显著增大,饱和输出电压基本保持不变。暗信号的退化是因为位移效应在体硅内引入大量体缺陷增加了耗尽区内热载流子产生率,暗信号非均匀性的退化主要来自于器件受中子辐照后在像素与像素之间产生了大量非均匀性的体缺陷能级。另外,还在样品芯片上引出了独立的像素单元测试管脚,测试了不同积分时间下像素单元输出信号。     

The study on optically stimulated luminescence dosimeter based on the SrS：Eu,Sm and CaS：Eu,Sm

With the increasing use of nuclear energy, there is a need for a wider range of efficient dosimeters for radiation detection and assessment. There has been a tremendous growth in the development of radiation detectors and devices in the past few decades. In recent years, the development of new materials for radiation dosimetry has progressed significantly. Alkaline earth sulfides （AES） have been known for a long time as excellent and versatile phosphor materials. In the present investigation, a number of phosphor samples such as mono-, binary and ternary sulfides of alkaline earths （II^a-VI^b） have been prepared and their TL properties have been studied with respect to exposure （x-ray） response and fading. In this paper, some results on SrS：Eu, Sm and CaS：Eu, Sm phosphors are presented. A type of novel OSL dosimeter is described. The dosimeter takes advantage of the characteristics of charge trapping materials SrS：Eu, Sm and CaS：Eu, Sm that exhibit optically stimulated luminescence （OSL）. The measuring range of the dosimeter is from 0.01 to 1000 Gy. The OSL dosimeters provide capability for remote monitoring radiation locations which are difficult to access and hazardous. This equipment is relatively simple, small in size and has low power consumption. The device is suitable for space radiation dose exploration. In addition, it also can be used in IC and other radiation occasions and has good prospects.