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131.
Haiyan Chen Jizhi Dai Yongzhi Liu 《International Journal of Infrared and Millimeter Waves》2004,25(12):1791-1798
IR integrated photonic amplifiers at 1.55m operation will have good foreground in optical phasedarray radars for splitters and signal processing. The saturation gain characteristics of IR integrated photonic waveguide amplifiers (taken Er3+Yb3+ co-doped phosphate glass waveguide amplifiers as an example) are studied theoretically. For the homemade laser glass materials the calculated saturation intensities are 2.22kw /cm2 for signal and 10.15kw/cm2 for pump. The effects of absorption saturation of signal and pump lights on the gain of amplifiers are discussed. 相似文献
132.
The electro-optic (E-O) properties of the slab polymer waveguide induced by electric poling have been studied experimentally. The thin film waveguide was prepared by a synthesized polymer polypelargonamide and poled by applying voltage between the electrodes. I–V curves and E-O characteristics of the polymer films were in-situ measured during poling. In order to evaluate the molecular dipole orientation under the poling field, the absorption spectra of this film was observed by FTIR. The E-O performance of the polymer slab film was also estimated by the Mach–Zehnder interferometer. 相似文献
133.
134.
New variational formulation to compute propagation constants is proposed. Based on it, vector finite element method is proved to exclude spurious modes provided finite elements possess discrete compactness property. Convergence analysis is conducted in the framework of collectively compact operators. Reported theoretical results apply to a wide class of vector finite elements including two families of Nedelec and their generalization, the -edge elements. Numerical experiments fully support theoretical estimates for convergence rates.
135.
ZhuJianxin 《高校应用数学学报(英文版)》2000,15(4):443-452
In this paper, a local orthogonal transformation is created to transform the Helmholtz waveguide with curved interface to the one with a flat interface within the two-layer medium, and the Helmholtz equation uxx uzz k^2(x,z)u=0 is transformed to Vxx αVzz βVz γV=0. Numerical results demonstrate that the transformation is more feasible. This transformation is particularly useful for the research on wave propagation in acoustic waveguide. 相似文献
136.
V. K. Kiseliov 《International Journal of Infrared and Millimeter Waves》2000,21(2):163-179
The paper considers an optimum sectional waveguide taper (OSWT) which at a shortest length of the transition region provides nearly adiabatic propagation of the fundamental mode between circular, widely different in diameter quasioptical transmission lines of class hollow dielectric waveguide (HDW). Derived as a consequence of coaxial circular-horn sections, the OSWT offers all the advantages of a simple geometry and lends itself to simple fabrication techniques. The relationships among the critical geometrical parameters and the loss calculation formulae are presented. The comparison studies show that even at a few sections, the OSWT is almost as good in performance as the parabolic taper, but the OSWT is much better from a mechanical viewpoint. And compared to the ordinary linear taper, the OSWT allows essential cut in length and loss with the broadbandness kept. The HDW-based four-sectional OSWT has been fabricated and tested in a quite broad wave range 2,5-8 mm. The testing results lend a good support to the analytical formulae lying at the basis of the design software. 相似文献
137.
V. Tamo?iūnas V. Shugurov M. Tamo?iūnien? K.-F. Berggren L. Knishevskaya 《International Journal of Infrared and Millimeter Waves》2000,21(7):1113-1117
In this paper we present a method to solve Maxwell's equations that enables to compute waveguide structure containing a semiconductor triangular prism. The numerical study has showed that the triangular prism in the waveguide has a wider frequency band in comparison with a square rod under equal conditions. The reflection coefficient dependencies on frequency, prism size and its permittivity have been computed. The algorithm and computer programme have been tested and compared with the numerical results and experimental data of the paper [1] with good agreement. 相似文献
138.
小极化子(Nb4+Li)荧光处于700—950 nm谱段,对不同化学还原程度同组分的纯铌酸锂晶体的研究表明荧光的强度反映了化学还原程度的强弱.从小极化子浅层能级出发,提出以“1中心3级态跃迁”来描述小极化子的受激荧光过程.钛扩散铌酸锂光波导(Ti:LiNbO3)表面还原程度的均匀性可能在波导制造的热扩散过程中被破坏.在对铌酸锂波导表面、深部的扫描结果中,荧光的强度呈现出表面与深部、波导内与外的差异,表面的强度是深部的6—8倍.研究表明,利用非损伤性的极化子荧光谱,对加工过程热处理进行检控是非常有效的.同时,波导内与外的荧光强度差异间接反映了波导的横切面的外形. 相似文献
139.
提出了一种基于Mach-Zehder干涉仪(MZI)结构开关单元和Banyan网络的严格无阻塞4×4矩阵光开关.相对于Crossbar结构的7级单元级联,Banyan结构只需3级连接.分析了Banyan网络中交叉连接损耗与交叉角度的关系,交叉角30°时损耗为0.09 dB.优化设计了MZI开关单元结构,并制作了2×2光开关,测得插入损耗(IL)为-14 dB、串扰(XT)为-38 dB和功耗为450 mW.设计了基于Banyan网络的4×4光开关,连接波导交叉角为30°.基于光波导平面光波线路(PLC)技术,制作了严格无阻塞的SiO2波导4×4矩阵光开关,测得平均IL为3.95 dB、通道XT为-37 dB、偏振相关损耗(PDL)为0.4 dB、单通道开关功率约为670 mW及开关响应时间小于1 ms. 相似文献
140.