共查询到20条相似文献，搜索用时 15 毫秒
1.
本文用自由空间模简化及近似表示弱导多层介质光波导的辐射模.只要辐射方向与介质界面的角度不是很小,近似程度很好.将其应用于求解光栅耦合器的辐射损耗问题,使计算公式简化,用自由空间模计算的结果与用辐射模计算的结果比较接近,也与其它近似方法进行了比较. 相似文献
2.
本文用自由空间模简化及近似表示弱导多层介质光波导的辐射模.只要辐射方向与介质界面的角度不是很小,近似程度很好.将其应用于求解光栅耦合器的辐射损耗问题,使计算公式简化,用自由空间模计算的结果与用辐射模计算的结果比较接近,也与其它近似方法进行了比较. 相似文献
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Plasmonic waveguides and conventional dielectric waveguides have favorable characteristics in photonic integrated circuits. Typically, plasmonic waveguides can provide subwavelength mode confinement, as shown by their small mode area, whereas conventional dielectric waveguides guide light with low loss, as shown by their long propagation length. However, the simultaneous achievement of subwavelength mode confinement and low-loss propagation remains limited. In this paper, we propose a novel design of an alldielectric bowtie waveguide, which simultaneously exhibits both subwavelength mode confinement and theoretically lossless propagation. Contrary to traditional dielectric waveguides, where the guidance of light is based on total internal reflection, the principle of the all-dielectric bowtie waveguide is based on the combined use of the conservation of the normal component of the electric displacement and the tangential component of the electric field, such that it can achieve a mode area comparable to its plasmonic counterparts. The mode distribution in the all-dielectric bowtie waveguide can be precisely controlled by manipulating the geometric design. Our work shows that it is possible to achieve extreme light confinement by using dielectric instead of lossy metals. 相似文献
5.
Chih T’sung Shih Zhi Wei Zeng Yin Cheng Chang Yao-Jen Lee Shiuh Chao 《Optical Review》2009,16(4):413-415
We provided a single-mode bent MOS-cross-section rib waveguide design with 0.9 dB/cm bending loss at 25 μm bending radius.
The peak position for the TE-like mode was tuned to the gate oxide around which the maximum amount of free carriers are accumulated
to optimize the free carrier dispersion effect. 相似文献
6.
本文将作为参考波导的圆介质波导模式的特征方程进行了有效的近似简化,使之成为独立的四个简单特征方程组。利用这些方程组作为参考波导的特征方程来计算各种复杂波导的传输参数时,能够大大简化计算工作。 相似文献
7.
Optical resonators are important devices that control the properties of light and manipulate light–matter interaction. Various optical resonators are designed and fabricated using different techniques. For example, in coupled resonator optical waveguides, light energy is transported to other resonators through near‐field coupling. In recent years, magnetic optical resonators based on LC resonance have been realized in several metallic microstructures. Such devices possess stronger local resonance and lower radiation loss compared with electric optical resonators. This study provides an overall introduction on the latest progress in coupled magnetic resonator optical waveguide (CMROW). Various waveguides composed of different magnetic resonators are presented and Lagrangian formalism is used to describe the CMROW. Moreover, several interesting properties of CMROWs, such as abnormal dispersions and slow‐light effects, are discussed and CMROW applications in nonlinear and quantum optics are shown. Future novel nanophotonic devices can be developed using CMROWs. 相似文献
8.
The extended boundary condition method is applied to both circular and elliptical regions for calculating cutoff frequencies Vc of weakly guiding optical waveguides, which consist of a uniform cladding and a core with arbitrary shape and index profile. The frequency shift formula method is explained by means of the extended boundary condition method on circular regions. Comparing the method with analytic and other rigorous methods, we show that it is indeed a powerful tool. Numerical results confirm that the mode designation and arrangement order in elliptical and rectangular waveguides are, in general, dependent on the aspect ratio. 相似文献
9.
George P. Zograf Alexander S. Timin Albert R. Muslimov Ivan I. Shishkin Alexandre Nomin Jaafar Ghanbaja Pintu Ghosh Qiang Li Mikhail V. Zyuzin Sergey V. Makarov 《Laser u0026amp; Photonics Reviews》2020,14(3)
All‐dielectric nanophotonics becomes a versatile tool for various optical applications, including nanothermometry and optical heating. Its general concept includes excitation of Mie resonances in nonplasmonic nanoparticles. However, the potential of resonant dielectric nanoparticles in drug delivery applications still has not been fully realized. Here, optically resonant dielectric iron oxide nanoparticles (α‐Fe2O3 NPs) are employed for remote rupture of microcontainers used as a drug delivery platform. It is theoretically and experimentally demonstrated that α‐Fe2O3 NPs have several advantages in light‐to‐heat energy conversion comparing to previously used materials, such as noble metals and silicon, due to the broader spectral range of efficient optical heating, and in enhancement of thermally sensitive Raman signal. The α‐Fe2O3 NPs embedded into the wall of universal drug carriers, polymer capsules, are used to experimentally determine the local temperature of the capsule rupture upon laser irradiation (170 °C). As a proof of principle, the delivery and remote release of anticancer drug vincristine upon lowered laser irradiation (4.0× 104 W cm−2) using polymer capsules modified with the α‐Fe2O3 NPs is shown. The biological tests are performed on two primary cell types: i) carcinoma cells, as an example of malignant tumor, and ii) human stem cells, as a model of healthy cells. 相似文献
10.
The paper provides theoretical analysis of planar antiresonant reflecting optical waveguides (ARROWs) with thin cores. It is shown that the appropriate choice of the cladding system parameters enables fabrication of thin-core ARROWs with all desired properties, such as low-loss single-mode operation and high refractive-index sensitivity of ARROW mode attenuation. 相似文献
11.
Study of the Leakage Loss in a Silica-on-Silicon Slab Waveguide 总被引：1，自引：0，他引：1
A simple and efficient method for studying the leakage loss in a conventional silica-on-silicon planar waveguide is presented. The magnitude of the leakage loss is obtained by calculating the complex propagation constant of the leaky waveguide structure. The dependence of the leakage loss on the thickness of the silica buffer layer (as well as the thickness of the silica upper-cladding layer) is investigated. Numerical results are presented and compared to those calculated with the beam propagation method. 相似文献
12.
K. W. Benoist J. L. Joppe M. J. Vellekoop M. K. Smit 《Fiber and Integrated Optics》2013,32(4):249-253
The total deflection of an optical guided wave by a surface acoustic wave (SAW) in a silicon-based SiO2/AL2O3/SiO2 optical waveguide structure is reported. The SAW is generated by an interdigital transducer with piezoelectric ZnO deposited on top of the optical waveguide structure. 相似文献
13.
A. Tseronis D. Tsilimantos N. Uzunoglu 《International Journal of Infrared and Millimeter Waves》2005,26(2):279-295
Radiation phenomena observed in a wedge shape ended dielectric slab waveguide are analyzed using mode matching technique. The case of transverse electric polarization (TE) being parallel to dielectric slab waveguide is assumed. In order to describe the fields in the wedge region, a stack of dielectric plates is assumed and in each layer the fields are expanded in terms of the mixed spectrum of guided and radiated modes. A similar expansion is used in the constant thickness slab waveguide while in free space medium a continuous-radiation mode expansion is used. Then a mode matching approach is applied, incorporating the orthogonality properties of mixed spectrum modes, in order to compute the wave fields inside the dielectric slab waveguide and wedge medium. Mode matching is achieved by discretizing the continuous radiation mode spectrum leading into a numerically stable solution provided a sufficient large number of points are used to convert integrals into finite summations. Numerical computations are carried out for various wedge geometries and shapes including linear and exponential profiles. 相似文献
14.
李元洲;刘俊琛;宋军 《光学学报》2013,33(s2):213001--1
基于氢化非晶硅光子工艺技术,单片集成了具有圆孔缺陷的刻蚀衍射光栅(EDG)微光谱仪,构建了一种高灵敏的折射率传感器。通过边界积分算法,精确分析了不同圆孔缺陷尺寸、缺陷位置和缺陷形状对探测灵敏度的影响。结果证明传感器的探测灵敏度和工艺容差性都随圆孔缺陷直径而改变,且能提供高传感灵敏度的共振散射缺陷往往具有相对较低的工艺容差性,在实际应用中需要根据要求对两者做折中考虑。研究结果证明圆孔缺陷位置对传感灵敏度几乎没有影响,但当圆孔缺陷更靠近输入光波导末端时可探测性更强;并且缺陷小的非正圆度对传感灵敏度的改变是可接受的。 相似文献
15.
金属包层渐变折射率介质光波导的传输特性与损耗 总被引：6，自引：2，他引：6
用金属包层介质光波导损耗的微扰理论及藉助多层近似法用递推公式分析渐变折射率波导传播常数的方法,对几种类型的金属包层渐变折射率介质光波导的传输特性与损耗进行分析和讨论,得到了与精确数值计算结果相吻合的结果. 相似文献
16.
Alexander S. Shalin Pavel Ginzburg Pavel A. Belov Yuri S. Kivshar Anatoly V. Zayats 《Laser u0026amp; Photonics Reviews》2014,8(1):131-136
In order to achieve interaction between light beams, a mediating material object is required. Nonlinear materials are commonly used for this purpose. Here a new approach to control light with light, based on a nano‐opto‐mechanical system integrated in a plasmonic waveguide is proposed. Optomechanics of a free‐floating resonant nanoparticle in a subwavelength plasmonic V‐groove waveguide is studied. It is shown that nanoparticle auto‐oscillations in the waveguide induced by a control light result in the periodic modulation of a transmitted plasmonic signal. The modulation depth of 10% per single nanoparticle of 25 nm diameter with the clock frequencies of tens of MHz and the record low energy‐per‐bit energies of 10−18 J is observed. The frequency of auto‐oscillations depends on the intensity of the continuous control light. The efficient modulation and deep‐subwavelength dimensions make this nano‐optomechanical system of significant interest for opto‐electronic and opto‐fluidic technologies. 相似文献
17.
Dan Zhang Hongting Jia Kiyotoshi Yasumoto 《International Journal of Infrared and Millimeter Waves》2008,29(9):823-831
A problem of coupling between conventional dielectric waveguides and a two-dimensional photonic crystal waveguide is analyzed,
using the Fourier series expansion method combined with the absorbing boundary condition of a perfectly matched layer (PML).
A novel structure for the input and output ends of the photonic crystal waveguide is proposed to increase the coupling efficiency.
Numerical examples are demonstrated and discussed to validate the effectiveness of the proposed structure. 相似文献
18.
Lluí as Torner Concepci an Santos Juan P. Torres Dumitru Mihalache 《Fiber and Integrated Optics》1994,13(3):271-280
The existence of new hybrid waveguide modes of properly tailored integrated optical waveguides consisting of ultrathin films clad by positive birefringent media is pointed out. 相似文献
19.
A method to design a corrugated optical waveguide filter by modulating the corrugation width profile is proposed. This method is based on combined applications of the Fourier transformation and the F-matrix formalism. The method achieves the spatial profile of the corrugation width required to design a filter with any specified spectral profile of the reflection coefficient. The idea of the technique is that the spatial variation of the effective refractive index can be transformed, with the help of the F-matrix formalism, to variation of the corrugation width while maintaining a constant amplitude of the refractive index variation. Two examples are given applying the technique to the design of optical waveguide filters with reflectivity profiles of two- and four-rejection bands. 相似文献
20.
椭圆傅里叶级数展开法和椭圆光波导的截止频率 总被引：2，自引：0，他引：2
与严格马丢（Ｍａｔｈｉｅｕ）函数、有限元法等许多典型方法及一些实验测试的比较表明,本文提出的计算弱导椭圆光波导的椭圆傅里叶级数展开法具有通用、准确、高效、简便的优点。 相似文献