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71.
介绍了一种新型的光纤传感器,采用热刻-酸蚀法在光纤上形成一些周期性刻纹结构,使得感受应变量的部分成为光纤本身的固有结构。这种光纤传感器具有线性、可重复的输入、输出响应且没有滞后效应,与其它传感器相比其最大的优点是灵敏度高、外形尺寸小。 相似文献
72.
本文报道了PCVD法数据光纤的研制,包括光纤设计、工艺流程及关键工艺问题,还给出了该数据光纤产品性能的统计结果。 相似文献
73.
关于光子学与光电子学 总被引:4,自引:0,他引:4
本文论述了光了学和光电子学的有关情况,以及光子学与光电子学的讨论中出现的几中不同的观点,展望面向21世纪的光子学在我国信息产业中的重要意义。 相似文献
74.
利用绝热扰动法研究了色散缓变光纤中Raman孤子自频移效应,得到了色散缓变光纤中Raman孤子自频移的表达式。结果表明:光纤色散变化率存在一个可以有效抑制孤子自频移的阈值,当光纤色散变化率大于这个阈值时,色散缓变光纤可以抑制孤子自频移,而当光纤色散变化率小于这个阈值时,色散缓变光纤不仅不能抑制孤子自频移,反而加剧孤子自频移。 相似文献
75.
本文从理论上研究了四波混频在多级放大频分复用光通信系统中的特性,提出了一种消除四波混频串扰的新方法,该方法只需适当选择信道间隔,无需增添其它器件,因而更有利于在实际光通信系统当中的应用。 相似文献
76.
A. M. Fernndez 《Advanced functional materials》1998,8(1):1-8
The electrochemical bath used for growing device-quality CIS (CuInSe2) thin films by co-deposition as well as layer-by-layer (LBL) deposition was characterised and optimised with respect to the film properties. The bath composition was varied by changing the Cu, In and Se ion concentrations in specific ratios in both co-deposition and LBL deposition. The film properties were analysed using techniques such as SEM (scanning electron microscopy), EPMA (electron probe microanalysis), AES (Auger electron spectroscopy) and XRD (X-ray diffraction). The structural, morphological and compositional properties of the films were characterised and their variation is attributed to the bath composition and growth conditions. © 1998 John Wiley & Sons, Ltd. 相似文献
77.
G. Marin S. M. Wasim G. Sánchez Pérez P. Bocaranda A. E. Mora 《Journal of Electronic Materials》1998,27(12):1351-1357
A new method to grow single crystals with stoichiometry close to 1:1:2 of CuInTe2, an important member of the Cu-III-VI2 family of semiconductors is described. This consists of tellurization in the liquid phase of stoichiometric Cu and In and
later solidification under directional freezing. It is found from energy dispersive spectroscopy that the ingots obtained
with the evaporation temperature (Tt) of Te at 590 and 635°C were very close to the ideal stoichiometry 1:1:2. Samples of all ingots obtained with Tt between 530 and 690°C, as studied by x-ray and differential thermal analysis, were of single phase having chalcopyrite structure
and p-type conductivity. Optical and electrical characterization of different ingots were made. The acceptor ionization energy
EA and the density of states effective mass m
p
*
of the holes are estimated from the temperature dependence of the hole concentration p in samples of different ingots. m
p
*
= (0.78 ± 0.02) me agrees quite well with the reported value. From a combined analysis of the variation of EA with p1/3 and the knowledge of molecularity and valence stoichiometry of each sample, it is established that the shallow acceptor level
observed in different samples with EA (0) ⋍ 30 meV is due to VIn. 相似文献
78.
CsLiB6O10 (CLBO) thin films are grown on Si (100) and (111) substrates using lower index SiO2 and CaF2 as buffer layers by pulsed KrF (248 nm) excimer laser ablation of stoichiometric CLBO targets over a temperature range of
425 to 725°C. A CaF2 buffer layer is grown on Si by laser ablation while SiO2 is prepared by standard thermal oxidation. From extended x-ray analysis, it is determined that CaF2 is growth with preferred orientation on Si (100) at temperatures lower than 525°C while on Si (111) substrate, CaF2 is grown epitaxially over the temperature range; this agrees well with observed reflection high energy electron diffraction
patterns. X-ray 2θ-scans indicate that crystalline CLBO are grown on SiO2/Si and CaF2/Si (100). Analysis of reflectance spectra from CLBO/SiO2/Si yields the absorption edge at 182 nm. Surface roughness of the CaF2 and CLBO/CaF2/Si film are 19 and 15 nm, respectively. This relatively rough surface caused by the ablation of wide bandgap CaF2 and CLBO limits the application of CLBO for waveguiding measurement. 相似文献
79.
W. Hu Florence Y. M. Chan D. P. Webb Y. C. Chan Y. W. Lam 《Journal of Electronic Materials》1996,25(12):1837-1840
The optical properties of hydrogenated amorphous silicon thin films prepared by a new thermocatalytic plasma enhanced chemical
vapor deposition (PECVD) method are here reported for the first time. The transmission spectrum of the film, deposited at
a rate of 1.5 nm/s, was measured between 500 and 1100 nm. The envelopes of the transmission spectrum interference maxima and
minima were analyzed to reveal the absorption coefficient α(λ@#@), the refractive indexn(λ), the average thickness of the film (791 nm) and the variation of the thickness (11.4 nm), using an analysis which takes into
account film inhomogeneity. The modified Newton's method of numerical analysis was used to obtain the optical parameters.
The optical band gap ε0} was determined to be 1.69 eV from the absorption coefficient spectrum, commensurate with values quoted for lower deposition
rate PECVD films. The value for ε0}, the small variation of the film thickness, and a value for the defect density of 3.7 x 1015}cm-3} determined for similar material in other work indicate that the thermocatalytic PECVD method can produce acceptable quality
films at a high deposition rate. 相似文献
80.