共查询到19条相似文献,搜索用时 93 毫秒
1.
2.
宽禁带半导体材料技术 总被引:1,自引:0,他引:1
李宝珠 《电子工业专用设备》2010,39(8):5-10,56
宽禁带半导体材料是一种新型材料,具有禁带宽度大、击穿电场高、热导率高等特点,非常适合于制作抗辐射、高频、大功率和高密度集成电子器件;利用其特有的禁带宽度,还可以制作蓝光、绿光、紫外光器件和光探测器件,能够适应更为苛刻的生存和工作环境。在宽禁带半导体材料中,具有代表性的是碳化硅(SiC)、氮化镓(GaN)、氮化铝(AlN)、金刚石以及氧化锌(ZnO),综合叙述了这些材料的特性、发展现状和趋势;并介绍了SiC、GaN、ZnO材料的应用情况和代表性器件的研究进展。 相似文献
3.
4.
傅恩生 《激光与光电子学进展》2003,40(12):7-10
提出用带有半导体光学放大器的塞纳克干涉仪开关对全光波长和脉宽变换,这种开关结构简单,开关速度不受半导体载流子恢复时间限制。输入数据的脉宽1.5ps被变换成24-18.1ps。在1539nm输入数据波长变换为可调谐波长,带宽为15nm(1550—1565nm)。 相似文献
5.
6.
半导体光放大器(SOA)非线性偏振旋转效应的光开关具有开关速度快、易集成等优点,其开关操作可以通过改变注入SOA中的电流而获得。这种偏振光开关的性能主要受注入光功率与控制电流的大小范围来决定。基于SOA中的偏振主态的概念,分析了非线性偏振旋转效应与控制电流的关系,并对不同功率的注入光进行了偏振旋转实验,分别实现了偏振光开关的操作。实验结果表明:随着注入光功率的增加可以提高光开关的分光比,有效改进光开关的性能。当注入光为5 dBm时,光开关的分光比与消光比均可达到30 dB。 相似文献
7.
8.
9.
10.
11.
Nieubor N. Panajotov K. Goulet A. Veretennicoff I. Thienpont H. 《Photonics Technology Letters, IEEE》1998,10(7):973-975
A polarization-switching VCSEL is combined with an anisotropic diffractive optical element to demonstrate, for the first time, reconfigurable free-space optical interconnects at a rate of 30 MHz. The same set of components is also used in a proof-of-principle demonstrator for data transparent reconfigurable optical interconnects at a bit rate of 1 MHz and a reconfiguration rate of 40 kHz 相似文献
12.
13.
ZnSe以其优异的光学性能与机械性能,一直是光学零件的首选材料之一。光学窗口、光学透镜等光学零件的制作成本很大程度上取决于光学材料的可加工性,加工成本占制作总成本的50%以上。从微观结构上来看,光学晶体材料的可加工性又与晶粒尺寸相关。文中采用物理气相沉积(PVD)法制备了PVDZnSe红外光学材料,并从沉积温度与原料性能两个方面研究了PVDZnSe制备工艺对其晶粒尺寸和可加工性的影响。研究表明:在920、960、1 000 ℃三个温度条件下,随着沉积温度升高,PVDZnSe材料晶粒呈现增加的趋势,其尺寸范围分别为20~180 μm、300~2000 μm和1 200~2 800 μm。在相同工艺参数条件下,选用粒径分别为2~10 μm、10~20 μm和300~2 000 μm的三种ZnSe原料制备PVDZnSe。随着原料ZnSe晶粒尺寸的增加,所得PVDZnSe的晶粒尺寸显著增大。结果表明,随着晶粒尺寸增加,脆性指数也相应增加,即PVDZnSe可加工性能在逐渐变差。研究还发现,在一定的晶粒尺寸范围内,材料的透过率差别不大,在2~14 μm波长范围内,PVDZnSe材料的平均透过率均能达到70%以上。该研究为PVDZnSe材料在光学零件领域的应用提供了实践经验和有力的技术支撑。 相似文献
14.
利用光栅侧面耦合技术多为单波长或窄带光耦合,用于光纤激光器泵浦、光波导集成等领域,而用于可见光宽带耦合的研究很少。通过在波导上集成亚波长衍射光栅结构,可以引导太阳光在波导的侧面进行出光汇集,作为一种新型的太阳能集光器结构。利用时域有限差分算法软件(FDTD)对光栅结构进行仿真,以获得最大衍射效率的光栅结构参数,并对不同入射角度下的衍射耦合效率进行了分析。结果显示,在宽波段的光谱范围内,以上光栅结构均达到较好的衍射效率,其中闪耀光栅衍射效率最大,其衍射效率可达48.8%。这种利用亚波长衍射光栅结构的小型集光器有望应用在有关太阳能能量的收集应用中,例如照明、太阳能电池等。 相似文献
15.
A three branch digital optical switch in polymers with a crosstalk of -30 dB is presented. Its crosstalk is insensitive to increasing heat power, which is the main advantage to ordinary DOS 相似文献
16.
17.
An optical packet switch based on WDM technologies 总被引:6,自引:0,他引:6
Fow-Sen Choa Zhao X. Xiuqin Yu Lin J. Zhang J.P. Gu Y. Ru G. Guansong Zhang Longjun Li Huiping Xiang Hadimioglu H. Chao H.J. 《Lightwave Technology, Journal of》2005,23(3):994-1014
Dense wavelength-division multiplexing (DWDM) technology offers tremendous transmission capacity in optical fiber communications. However, switching and routing capacity lags behind the transmission capacity, since most of today's packet switches and routers are implemented using slower electronic components. Optical packet switches are one of the potential candidates to improve switching capacity to be comparable with optical transmission capacity. In this paper, we present an optically transparent asynchronous transfer mode (OPATM) switch that consists of a photonic front-end processor and a WDM switching fabric. A WDM loop memory is deployed as a multiported shared memory in the switching fabric. The photonic front-end processor performs the cell delineation, VPI/VCI overwriting, and cell synchronization functions in the optical domain under the control of electronic signals. The WDM switching fabric stores and forwards cells from each input port to one or more specific output ports determined by the electronic route controller. We have demonstrated with experiments the functions and capabilities of the front-end processor and the switching fabric at the header-processing rate of 2.5 Gb/s. Other than ATM, the switching architecture can be easily modified to apply to other types of fixed-length payload formats with different bit rates. Using this kind of photonic switch to route information, an optical network has the advantages of bit rate, wavelength, and signal-format transparencies. Within the transparency distance, the network is capable of handling a widely heterogeneous mix of traffic, including even analog signals. 相似文献
18.
Contrast enhancement for the infrared vein image of leg based on the optical angular spectrum theory
The near-infrared (NIR) imaging method was required for the diagnosis of varicose veins, which mean that the veins have become enlarged and twisted on leg. In some cases, the hair on leg could be dense and formed a noise during the NIR vein images. Here, a preliminary treatment to filter out the effect of hair on the NIR image was carried out. The filter design was based on the optical angular spectrum theory to select a threshold spatial frequency in order to separate a specific vein infrared image of leg from that of the hair. An experimental setup combined a NIR light, a charge coupled device camera with the filtering algorithms which were implemented to prove the effectiveness on the hair noise removal. The results demonstrated that an annulus Butterworth filter was more effective to reduce the hair noise and simultaneously enhance the contrast of the venous images on leg than the others. This design processed a NIR image in terms of an optical angular spectrum theory, thereby an all-optical treatment for the contrast enhancement of a veins image being possible in the future. 相似文献
19.
提出一种基于ATR技术的的新型光开关器件.该光开关是利用聚合物薄膜的电光效应,通过控制导模的耦合效率,进一步控制反射光强来实现光的通断.理论与实验表明:该器件具有响应速度快、消光比大、损耗小、稳定性高、制备工艺简单和成本低廉等特点. 相似文献