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31.
Y. Zhang T. M. Benson P. Sewell A. Vukovic D. Zhang W. J. Pan A Loni D. Furniss A. B. Seddon 《Optical and Quantum Electronics》2006,38(1-3):97-110
This paper presents our recent simulation results and novel designs of single mode large cross-section glass-based waveguides for photonic integrated circuits (PICs). Simulations were performed using an in-house Finite Difference (FD) based mode solver and the FD Beam propagation Method (FD-BPM). Our simulation results show that this innovative technology could provide a simplified means to couple optical energy efficiently between optical components in a single chip. This would provide the base for the future large-scale integration of optical components in PICs. The novel idea of using single mode large cross-section glass-based waveguides as an optical integration platform is an evolutionary innovative solution for the monolithic integration of optical components, in which the glass-based structures act both as waveguides and as an optical bench for integration. This allows easy and efficient optical coupling between optical components and optical fibres, removing costly and tedious alignment problems and considerably reducing optical coupling losses in PICs. We expect that the glass-based waveguide PICs technology will enable the emergence of a new generation of compact, reliable, high speed, and multifunctional devices. 相似文献
32.
Fe-doped TiO2 powder was prepared by high-energy ball milling, using TiO2 Degussa P-25 and α-Fe powders as the starting materials. The structure and magnetic properties of the Fe-doped TiO2 powder were studied by X-ray diffraction, 57Fe Mossbauer spectroscopy and vibrating sample magnetometer. The Reitveld refinement of XRD revealed that ball milling not only triggered incorporation of Fe in TiO2 lattice but also induced the phase transformation from anatase to rutile in TiO2 and consequently the milled Fe-doped TiO2 powder contained only rutile.57Fe Mössbauer effect measure showed that Fe atoms existed in Fe2+ and Fe3+ state, which were assigned to the solid solution FexTi1−xO2. The magnetization measurements indicated that the milled Fe-doped TiO2 powder was ferromagnetic above room temperature. The ferromagnetism in our milled Fe-doped TiO2 powder seemingly does not come from Fe and iron oxides particles/clusters but from the Fe-doped TiO2 powder matrices. 相似文献
33.
34.
Effects of Nb2O5 on thermal stability and optical properties of Er3+-doped tellurite glasses 下载免费PDF全文
Er3+-doped tellurite glasses with molar compositions of
xNb2O5-(14.7-x)Na2O--10ZnO--5K2O--10GeO2--
60TeO2--0.3Er2O3
(x=0, 3, 5, 7 and 9) have been investigated for developing 1.5~μm
fibre and planar amplifiers. The effects of Nb2O5 on the thermal stability
and optical properties of Er3+-doped tellurite glasses have been discussed.
It is noted that the incorporation of Nb2O5 (x=5) increases the thermal
stability of tellurite glasses significantly. Er3+-doped niobium tellurite
glasses exhibit a large stimulated emission cross-section (7.2\times 10-21-
10.7×10-21~cm2 and the gain bandwidth, FWHM×\sigmae^{\rm peak} (274\times 10-28 - 480×10-28~cm3), which are
significantly higher than that of silicate and phosphate glasses. In addition, the
intensity of upconversion luminescence of the Er3+-doped niobium tellurite
glasses decreases rapidly with increasing Nb2O5 content. As a result,
Er3+-doped niobium tellurite glasses might be a potential candidate for
developing laser or optical amplifier devices. 相似文献
35.
Let A and B be two finite subsets of a field
. In this paper, we provide a non-trivial lower bound for {a+b:aA, bB, and P(a,b)≠0} where P(x,y)
[x,y]. 相似文献
36.
用长脉冲激光(脉冲宽度150μs,波长1.06μm)辐照高温烧结的YBa_2Cu_3O_(7-x)靶,在6Pa的氧气压强下,巳在(100)YSZ单晶衬底上原位生成YBa_2Cu_(?)O_(7-x)超导膜。衬底置于750℃的加热器上,衬底与靶之间的距离5cm,用该法制得的薄膜光亮坚实,正常态呈金属性,零电阻温度为84.7K。用XRD和SEM对薄膜进行了分析研究。 相似文献
37.
Temperature-dependent current-voltage measurement was employed to study the band offsets of the In0.30Ga0.70As/In 0.29Al0.71As heterojunction. The conduction band discontinuity was determined to be 0.71±0.05 eV which corresponds to a conduction band offset to bandgap difference ratio ~0.66. The comparison between experimental and theoretical results is presented 相似文献
38.
氟碳铈矿/直氟碳钙铈矿混层结构中新规则混层矿物的超微结构研究 总被引:4,自引:0,他引:4
用电子衍射和晶格像技术研究了钙稀土氟碳酸盐矿物中的氟碳铈矿(B)/直氟碳钙铈矿(S)混层结构,发现并确定了B_4S_4、B_8S_6、B_1S_6、B_7S_4和B_2S_15种新规则混层矿物的对称性、晶胞参数及理论晶体化学式。根据所获得的高分辨晶格像真实而直观地揭示出该类B_mS_n(m>n)型新规则混层矿物的长周期有序堆垛结构特征及变化规律。 相似文献
39.
40.
Design of a 3780-point IFFT processor for TDS-OFDM 总被引:2,自引:0,他引:2
Zhi-Xing Yang Yu-Peng Hu Chang-Yong Pan Lin Yang 《Broadcasting, IEEE Transactions on》2002,48(1):57-61
This correspondence presents a design of 3780-point IFFT processor for TDS-OFDM terrestrial DTV transmitter using FPGA. It demonstrates the algorithm design and error analysis of the processor, which can achieve a throughput of 7.56M complex IFFT operations per second. This design meets the signal-to-quantization noise ratio requirement of the TDS-OFDM system. It consists of two FPGA and one dual-port RAM. The data stream pipeline algorithm is implemented 相似文献