Defect modes in two-dimensional photonic crystals consisting of nearly-free-electron metals are considered. To avoid any time-consuming time convolution, modified time stepping formulae are used in a finite-difference...Defect modes in two-dimensional photonic crystals consisting of nearly-free-electron metals are considered. To avoid any time-consuming time convolution, modified time stepping formulae are used in a finite-difference time-domain (FDTD) method. Compared to the FDTD transmission spectra method, the present method significantly reduces the computation domain. With the present method one can also find defect modes that are not excited by the incident plane wave in the FDTD transmission spectra method.展开更多
A theoretical analysis is presented for a channel drop tunnelling structure composed of a horizontal input channel, a vertical output channel and a multi-mode cavity in a photonic crystal. Criteria for a complete tran...A theoretical analysis is presented for a channel drop tunnelling structure composed of a horizontal input channel, a vertical output channel and a multi-mode cavity in a photonic crystal. Criteria for a complete transfer are derived for applications of wavelength division demultiplexing. The analytical results are verified with a numerical simulation using a finite difference time domain method. The vertical channel dropping tunnelling system makes the demultiplexing device much more compact, as compared to the conventional parallel channel dropping system.展开更多
An averaged field approach is suggested for obtaining the band structure of a photonic crystal when the dimension of the inclusions is much smaller compared with the longest period of the rectangular lattice of the ph...An averaged field approach is suggested for obtaining the band structure of a photonic crystal when the dimension of the inclusions is much smaller compared with the longest period of the rectangular lattice of the photonic crystal.The method is illustrated for the H-polarization of the 2-dimensional case.The band structure is obtained in an explicit and simple way.The method is verified numerically by comparing with the conventional plane-wave expansion method.展开更多
Guided modes in a two-dimensional photonic crystal consisting of nearly-free-electron metals are considered. To avoid time-consuming convolution, modified time-stepping formulae are used in a finite-difference time-do...Guided modes in a two-dimensional photonic crystal consisting of nearly-free-electron metals are considered. To avoid time-consuming convolution, modified time-stepping formulae are used in a finite-difference time-domain approach. The guided modes in the metallic photonic crystal waveguide are related to those in a conventional metallic waveguide. A cut-off frequency exists, and consequently a mode gap at low frequencies exists in the photonic crystal metallic waveguide.展开更多
基金Supported in part by the key project grant for the Division of Science and Technologies of Zhejiang provincial government(ZD0002).
文摘Defect modes in two-dimensional photonic crystals consisting of nearly-free-electron metals are considered. To avoid any time-consuming time convolution, modified time stepping formulae are used in a finite-difference time-domain (FDTD) method. Compared to the FDTD transmission spectra method, the present method significantly reduces the computation domain. With the present method one can also find defect modes that are not excited by the incident plane wave in the FDTD transmission spectra method.
基金Supported in part by the State Kay Laboratory of Modern Optical Instrumentation(Zhejiang University,China)under an open project grant and the Ministry of Education for overseas visiting scientists。
文摘A theoretical analysis is presented for a channel drop tunnelling structure composed of a horizontal input channel, a vertical output channel and a multi-mode cavity in a photonic crystal. Criteria for a complete transfer are derived for applications of wavelength division demultiplexing. The analytical results are verified with a numerical simulation using a finite difference time domain method. The vertical channel dropping tunnelling system makes the demultiplexing device much more compact, as compared to the conventional parallel channel dropping system.
基金Supported in part by the grant for the Chang Jiang special Professor(Ministry of Education,P.R.China)。
文摘An averaged field approach is suggested for obtaining the band structure of a photonic crystal when the dimension of the inclusions is much smaller compared with the longest period of the rectangular lattice of the photonic crystal.The method is illustrated for the H-polarization of the 2-dimensional case.The band structure is obtained in an explicit and simple way.The method is verified numerically by comparing with the conventional plane-wave expansion method.
基金Supported in part by the Key Project of the Division of Science and Technology of Zhejiang Province(ZD0002).
文摘Guided modes in a two-dimensional photonic crystal consisting of nearly-free-electron metals are considered. To avoid time-consuming convolution, modified time-stepping formulae are used in a finite-difference time-domain approach. The guided modes in the metallic photonic crystal waveguide are related to those in a conventional metallic waveguide. A cut-off frequency exists, and consequently a mode gap at low frequencies exists in the photonic crystal metallic waveguide.
