共查询到19条相似文献,搜索用时 296 毫秒
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平面光波导放大器中光场分布的一种计算方法 总被引:3,自引:1,他引:2
用交变隐式差分方向的时域有限差分法(ADI-FDTD)计算了掺Er3+玻璃平面光波导放大器中光场的分布.其算法简单,结果无条件稳定,能完全模拟波导中的光场特性. 相似文献
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交叉波导是集成光学中的一种重要的器件单元,针对大角度交叉波导的结构及折射率分布,运用基于广义道格拉斯算子的宽角多步有限差分光束传播法模拟大角度交叉波导的传输特性,数值计算出波导中的光场的分布。与Crank-Nicholson格式的有限差分光束传播法相比,该算法在几乎不增加计算时间和计算机内存资源的情况下,结合了广义道格拉斯格式的有限差分光束传播法截断误差小[只有o(△x)^4]和宽角多步法所具有较高精度的优点,是光波导器件理想的数值模拟工具。在此基础上计算分析了大角度交叉波导的输出分支波导的能量与交叉角度的关系,以及交叉角度对波导间能量耦合的影响。这为实际的设计制作光器件的工作提供了极好的基础。 相似文献
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基于光波在直波导和复合结构光子晶体中的传播特性,结合平面波展开法和时域有限差分法,提出并讨论了一种新型的超紧凑的光子晶体偏振光分束器. 它是由输入波导,分束结构和输出波导三部分组成. 对这种结构的三角晶格光子晶体光分束器的数值计算与模拟结果表明,该结构可以实现TE模和TM模的高效大角度分离,并且在通信波段设计尺寸小,这些特性使其在未来的集成光回路中有着重要的应用前景.
关键词:
偏振光分束器
能带结构
平面波展开法
时域有限差分法 相似文献
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半导体光放大器的耦合光纤形成的外腔反馈通过引入弯曲损耗得以抑制.通过对半导体光放大器有源波导引入对前、后向光场非对称散射损耗,以前向光场部分损耗为代价,反馈光场能量被分布式地较强辐射.时域有限差分法仿真研究表明,通过优化弯曲有源波导的结构,相对于通常的有源直波导,在相同的材料增益和输入、输出条件下,反馈可以下降10 dB以上.由此可以简化高增益半导体光放大器的器件结构. 相似文献
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H. W. Yang D. Xu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,64(2-3):387-392
This paper presents a parallel frequency-dependent finite-difference time-domain ((FD)2TD) method for plasma in the dispersive media. Results obtained with parallel and serial algorithms verify that parallel (FD)2TD has the same precision as the serial (FD)2TD, while the parallel approach could reduce the CPU time efficiently. A tunable filter is analyzed based on a one-dimensional photonic crystal containing a plasma defect by this method. The tunability of the photonic crystal filter can be achieved by adjusting the defect layer parameters instead of changing the dimension of photonic crystal. 相似文献
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A full-vectorial (FV) analysis of optical dielectric waveguide bends by using finite difference (FD) method in terms of magnetic field components is developed in a local cylindrical coordinate system. The perfectly matched layer absorbing boundary conditions via the complex coordinate stretching technique are incorporated into the FV wave equations for effectively demonstrating the leaky nature of waveguide bends, and a six-point FD scheme is constructed to approximate the cross-coupling terms for improving the convergent behavior. The leaky modes of a typical rib waveguide bend are calculated and the complex propagation constants and the field patterns for TE- and TM-like modes are obtained. Solutions are good agreement with those from the film mode matching method, which shows the validity and utility of the established method. 相似文献
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In many Fourier-transform spectroscopies, such as pulse magnetic resonance (NMR, EPR), time-domain signals are acquired. Parameters are extracted from these signals by fitting numerical simulations to the experimental data. At present, simulations are often performed in frequency domain (FD). These computations generate a list of frequencies and amplitudes associated with the complex exponential components evolving during one or several variable time intervals. In order to compare simulations with experiments, this peak list is converted to a finite-length time-domain (TD) signal. This can be achieved either by directly evoluting the exponentials in time (direct method) or by rounding their frequencies and binning their amplitudes into a frequency-domain array (histogram method). The first approach is equivalent to a brute-force TD simulation and is slow for a large number of peaks. The second approach is a fast, but very crude approximation and is usually applied without considering in detail the errors involved. A third method introduced and illustrated here is based on the convolution and deconvolution of a short finite impulse response filter kernel. This convolution approach is much faster than the direct method and by orders of magnitude more accurate than the histogram method. For both TD and FD signals a detailed analysis of the errors and of the associated computational costs is presented. The convolution approach is applicable to any simulation problem where TD signals consist of a large number of complex exponentials. In particular, it is the method of choice for simulating 1D and 2D electron spin echo envelope modulation (ESEEM) spectra of disordered systems. 相似文献
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Speed acquisition for image formation process through scattering medium is a challenge in optical coherence tomography (OCT) approach. Besides time domain (TD), spectral Fourier domain (FD) is now widely studied. By using a swept laser source, we demonstrate that a particular time domain OCT method (optical SISAM correlator) can be simultaneously implemented in a single set-up with the corresponding Fourier domain OCT approach (spectral interferometry). Then, FD-OCT and TD-OCT signals are obtained by processing a 3D “spatial-frequential” interferences pattern. We show that these two numerical approaches can be complementary when imaging in scattering medium is achieved. 相似文献
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基于有限差分束传播法的Mach-Zehnder型波导电光调制器的模拟设计 总被引:4,自引:0,他引:4
针对掺钛铌酸锂Mach-Zehnder型波导电光调制器的结构及折射率分布,运用有限差分束传播方法(FD BPM)进行模拟计算,取得了二维情况下的最佳设计尺寸.在此基础上,把所得的设计结果与原有的用快速傅里叶束传播方法(FFT BPM)所得的结果进行比较和分析.结果显示,运用有限差分束传播方法不仅取得了预期的结果,而且,这种方法比原有的快速傅里叶束传播方法更快捷和方便,是器件设计的理想和现实的数值模拟工具. 相似文献
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研究了用于光互连的聚硅氧烷多模光波导直接弯曲时弯曲损耗与圆弧曲率半径的关系。用Marcuse的直波导近似法理论计算了其弯曲损耗,理论计算表明弯曲损耗随模阶数的增加而变大,随半径的减少而变大;光在波导中传输时,总弯曲损耗出现阶跃式变化,并且曲率半径大于4 mm时,波导的弯曲损耗小于1dB/cm。用BeamPROP仿真软件仿真了5、10、20mm三种曲率半径下的传输光场情况。利用数字化散射法测量了其弯曲损耗,实验结果显示曲率半径在5~6mm时弯曲损耗值在0.55~0.8dB/cm之间,考虑所制备的聚硅氧烷直波导固有的传输损耗,实验值与理论值基本相符。 相似文献
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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