We investigate both experimentally and numerically a complex structure, where ＇face-to-face＇ Helmholtz resonance cavities （HRCs） are introduced to construct a one-dimensional acoustic grating. In this system, pair...We investigate both experimentally and numerically a complex structure, where ＇face-to-face＇ Helmholtz resonance cavities （HRCs） are introduced to construct a one-dimensional acoustic grating. In this system, pairs of HRCs can intensely couple with each other in two forms： a bonding state and an anti-bonding state, analogous to the character of hydrogen molecule with two atoms due to the interference of wave functions of sound among the acoustic local-resonating structures. The bonding state is a ＇bright＇ state that interferes with the Fabry-Pbrot resonance mode, thereby causing this state to break up into two modes as the splitting of the extraordinary acoustic transmission peak. On the contrary, the anti-bonding state is a ＇dark＇ state in which the resonance mode remains entirely localized within the HRCs, and has no contribution to the acoustic transmission.展开更多
Design of nonmagnetic optical isolators integrated with silicon waveguides is important for rapidly growing sil-icon photonics in optical communications.We introduce a silicon waveguide consisting of an array of compl...Design of nonmagnetic optical isolators integrated with silicon waveguides is important for rapidly growing sil-icon photonics in optical communications.We introduce a silicon waveguide consisting of an array of complex sinusoidal-shaped structures that create the designed time-dependent modulation of refractive indices.These time-dependent sinusoidal-shaped structures are engineered to have in-phase mode conversion only in one direc-tion,thus leading to asymmetric optical mode conversion in the silicon waveguide and one-way light transmission with high contrast ratios,confirmed by numerically simulated field maps and calculated transmission at the wavelength of 1550nm.Our design may offer another practical design to the compact chip-scale optical isolators in silicon waveguides.展开更多
基金Supported by the National Basic Research Program of China under Grant Nos 2012CB921503,2013CB632904 and 2013CB632702the National Natural Science Foundation of China under Grant No 1134006+2 种基金the Natural Science Foundation of Jiangsu Province under Grant No BK20140019the Project Funded by the Priority Academic Program Development of Jiangsu Higher Educationthe China Postdoctoral Science Foundation under Grant Nos 2012M511249 and 2013T60521
文摘We investigate both experimentally and numerically a complex structure, where ＇face-to-face＇ Helmholtz resonance cavities （HRCs） are introduced to construct a one-dimensional acoustic grating. In this system, pairs of HRCs can intensely couple with each other in two forms： a bonding state and an anti-bonding state, analogous to the character of hydrogen molecule with two atoms due to the interference of wave functions of sound among the acoustic local-resonating structures. The bonding state is a ＇bright＇ state that interferes with the Fabry-Pbrot resonance mode, thereby causing this state to break up into two modes as the splitting of the extraordinary acoustic transmission peak. On the contrary, the anti-bonding state is a ＇dark＇ state in which the resonance mode remains entirely localized within the HRCs, and has no contribution to the acoustic transmission.
基金Supported by the National Basic Research of China under Grant Nos 2012CB921503 and 2013CB632702the National Natural Science Foundation of China under Grant No 11134006the Priority Academic Program Development of Jiangsu Higher Education and FANEDD of China.
文摘Design of nonmagnetic optical isolators integrated with silicon waveguides is important for rapidly growing sil-icon photonics in optical communications.We introduce a silicon waveguide consisting of an array of complex sinusoidal-shaped structures that create the designed time-dependent modulation of refractive indices.These time-dependent sinusoidal-shaped structures are engineered to have in-phase mode conversion only in one direc-tion,thus leading to asymmetric optical mode conversion in the silicon waveguide and one-way light transmission with high contrast ratios,confirmed by numerically simulated field maps and calculated transmission at the wavelength of 1550nm.Our design may offer another practical design to the compact chip-scale optical isolators in silicon waveguides.
