Based on the radiation modes, an active control strategy is presented for sound radiation from elastic structures with an example of simply supported rectangular panel. The physical characteristics and mathematical me...Based on the radiation modes, an active control strategy is presented for sound radiation from elastic structures with an example of simply supported rectangular panel. The physical characteristics and mathematical meaning of the radiation modes are analyzed. The radiation efficiency of radiation mode falls off very rapidly with the increase of modes order at low frequency. A new control strategy is developed in which by canceling the adjoint coef- ficient of the first k radiation modes, the sound powers of the first k radiation modes is zero theoratically. The numerical calculation is made by using point force actuators as control forces.展开更多
We theoretically investigate transmission-type SPR sensors with novel metallic-dielectric mixed gratings by rig- orous coupled-wave analysis （RCWA）, compared to the conventional dielectric gratings based structure. ...We theoretically investigate transmission-type SPR sensors with novel metallic-dielectric mixed gratings by rig- orous coupled-wave analysis （RCWA）, compared to the conventional dielectric gratings based structure. It is found that the transmittance efficiency and the full width at half-maximum （FWHM） of the transmission curve can be modulated by increasing or decreasing the metallic part. Therefore, appropriate proportion of metal part will induce enhancement factor of sensor merit. Furthermore, this novel structure will also bring enhancement of resonant angle shift, which can be explained by plasmonie interpretation based on a surface limited increase of interaction area and excitation of localized surface plasmons （LSPs）. The proposed configuration has a wide range of potential applications not only as sensor but also other optical devices.展开更多
基金the National Natural Science Foundation of China (No.50075O36).
文摘Based on the radiation modes, an active control strategy is presented for sound radiation from elastic structures with an example of simply supported rectangular panel. The physical characteristics and mathematical meaning of the radiation modes are analyzed. The radiation efficiency of radiation mode falls off very rapidly with the increase of modes order at low frequency. A new control strategy is developed in which by canceling the adjoint coef- ficient of the first k radiation modes, the sound powers of the first k radiation modes is zero theoratically. The numerical calculation is made by using point force actuators as control forces.
文摘We theoretically investigate transmission-type SPR sensors with novel metallic-dielectric mixed gratings by rig- orous coupled-wave analysis （RCWA）, compared to the conventional dielectric gratings based structure. It is found that the transmittance efficiency and the full width at half-maximum （FWHM） of the transmission curve can be modulated by increasing or decreasing the metallic part. Therefore, appropriate proportion of metal part will induce enhancement factor of sensor merit. Furthermore, this novel structure will also bring enhancement of resonant angle shift, which can be explained by plasmonie interpretation based on a surface limited increase of interaction area and excitation of localized surface plasmons （LSPs）. The proposed configuration has a wide range of potential applications not only as sensor but also other optical devices.
