We propose a design and optimization for directional coupling in terahertz hybrid-cladding hollow waveguide. It is composed of two square hollow waveguides which touch each other and are surrounded by a metallic layer...We propose a design and optimization for directional coupling in terahertz hybrid-cladding hollow waveguide. It is composed of two square hollow waveguides which touch each other and are surrounded by a metallic layer. By employing the finite element method, the coupling performance and loss property are numerically investigated. Numerical results indi- cate that this directional coupler with hybrid-cladding can realize ultra-narrow-band coupling; it provides a low confinement loss performance： the confinement loss can reach as low as 6.27 × 10-5 cm- 1. Moreover, the further analyses of configura- tion and performance show that confinement loss and frequency range shift for the low-confinement-loss frequency regime can be realized and optimized by appropriately tuning the thickness values of the metallic and dielectric layer. In addition, through the further analysis of coupling performance, the possibilities of realizing ultra-narrow-band couplings in different frequency ranges are demonstrated. It is a powerful candidate for high precision optical fiber sensing, and communication in terahertz splitting fields.展开更多
The scalar two-dimensional finite difference time domain (FDTD) method is applied to simulate the mode field distribution of TE 0 of the waveguide grating coupler. Computer simulation shows that the same stable mode f...The scalar two-dimensional finite difference time domain (FDTD) method is applied to simulate the mode field distribution of TE 0 of the waveguide grating coupler. Computer simulation shows that the same stable mode field distribution pattern is obtained through the different kinds of driving sources. It is found that the optical field mode is determined by waveguide structure and optical wavelength other than the driving source.According to the mode field distribution, the optimum coupling efficiency can be predicted. Compared with another numerical methods,the CPU-time and memory elements of computer used by FDTD are much less.展开更多
In this work, we develop a simulation method based on supermode theory and transfer matrix formalism, and then apply it to the analysis and design of taper couplers for vertically integrated As2S3 and Ti: LiNbO3 hybri...In this work, we develop a simulation method based on supermode theory and transfer matrix formalism, and then apply it to the analysis and design of taper couplers for vertically integrated As2S3 and Ti: LiNbO3 hybrid waveguides. Test structures based on taper couplers are fabricated and characterized. The experimental results confirm the validity of the modeling method, which in turn, is used to analyze the fabricated couplers.展开更多
为满足X波段T/R组件定标和校正的需求,组件内部需集成小型化、高性能的耦合器。微带到带状线多阶小孔耦合器在弱耦合情况下具有宽带平坦的耦合特性、体积小、易于与射频有源电路集成,非常方便在T/R组件的LTCC多层基板上实现。在设计过程...为满足X波段T/R组件定标和校正的需求,组件内部需集成小型化、高性能的耦合器。微带到带状线多阶小孔耦合器在弱耦合情况下具有宽带平坦的耦合特性、体积小、易于与射频有源电路集成,非常方便在T/R组件的LTCC多层基板上实现。在设计过程中,首先根据多阶小孔耦合的基本理论和公式确定小孔的数量和分布特征,再依据实际布局的限制在电磁场仿真软件HFSS中建立参数化模型,最后通过HFSS的调谐优化确定最优的物理参数。仿真表明,该耦合器尺寸小于λ04,带内平坦度优于±0.1 d B。该耦合器完全达到设计要求,可广泛应用于X波段小型化宽带T/R组件中。展开更多
基金Project supported by the Specific Scientific and Technological Cooperation between China and Russia(Grant No.2010DFR80140)the National Natural Science Foundation of China(Grant No.51309059)
文摘We propose a design and optimization for directional coupling in terahertz hybrid-cladding hollow waveguide. It is composed of two square hollow waveguides which touch each other and are surrounded by a metallic layer. By employing the finite element method, the coupling performance and loss property are numerically investigated. Numerical results indi- cate that this directional coupler with hybrid-cladding can realize ultra-narrow-band coupling; it provides a low confinement loss performance： the confinement loss can reach as low as 6.27 × 10-5 cm- 1. Moreover, the further analyses of configura- tion and performance show that confinement loss and frequency range shift for the low-confinement-loss frequency regime can be realized and optimized by appropriately tuning the thickness values of the metallic and dielectric layer. In addition, through the further analysis of coupling performance, the possibilities of realizing ultra-narrow-band couplings in different frequency ranges are demonstrated. It is a powerful candidate for high precision optical fiber sensing, and communication in terahertz splitting fields.
文摘The scalar two-dimensional finite difference time domain (FDTD) method is applied to simulate the mode field distribution of TE 0 of the waveguide grating coupler. Computer simulation shows that the same stable mode field distribution pattern is obtained through the different kinds of driving sources. It is found that the optical field mode is determined by waveguide structure and optical wavelength other than the driving source.According to the mode field distribution, the optimum coupling efficiency can be predicted. Compared with another numerical methods,the CPU-time and memory elements of computer used by FDTD are much less.
文摘In this work, we develop a simulation method based on supermode theory and transfer matrix formalism, and then apply it to the analysis and design of taper couplers for vertically integrated As2S3 and Ti: LiNbO3 hybrid waveguides. Test structures based on taper couplers are fabricated and characterized. The experimental results confirm the validity of the modeling method, which in turn, is used to analyze the fabricated couplers.
文摘为满足X波段T/R组件定标和校正的需求,组件内部需集成小型化、高性能的耦合器。微带到带状线多阶小孔耦合器在弱耦合情况下具有宽带平坦的耦合特性、体积小、易于与射频有源电路集成,非常方便在T/R组件的LTCC多层基板上实现。在设计过程中,首先根据多阶小孔耦合的基本理论和公式确定小孔的数量和分布特征,再依据实际布局的限制在电磁场仿真软件HFSS中建立参数化模型,最后通过HFSS的调谐优化确定最优的物理参数。仿真表明,该耦合器尺寸小于λ04,带内平坦度优于±0.1 d B。该耦合器完全达到设计要求,可广泛应用于X波段小型化宽带T/R组件中。
