The resonance absorption of a multilayered bi-grating which consists of thin-film corrugated periodically in two directions is investigated. The absorption in a multilayered thin-film bi-grating has been of considerab...The resonance absorption of a multilayered bi-grating which consists of thin-film corrugated periodically in two directions is investigated. The absorption in a multilayered thin-film bi-grating has been of considerable interest since we can expect more complex behaviors in the absorption phenomen by virtue of the presence of double periodicity and multilayer structure. In solving the problem, we employed a computational technique based on modal expansion. Taking a sandwiched structure /Ag/SiO2/Ag/ for an example, we observed: 1) excitation of a single-interface surface plasmon mode at the lit surface of the 1st Ag layer with strong field enhancement for thick enough Ag layer case;2) excitation of coupled short-range or long-range surface plasmon modes at each surface between vacuum and Ag layers with strong field enhancements for thin enough Ag layer cases no matter with the thickness of SiO2 layers;3) enhancements of field at surfaces between Ag and SiO2 layers in some cases related with the thickness of SiO2 layers. The coupled plasmon modes were resulted by the resonance waves on four surfaces in these cases.展开更多
This paper reports on a new property of grating, namely spectral combination, and on bi-grating diffraction imaging that is based on spectral combination. The spectral combination characteristic of a grating is the ca...This paper reports on a new property of grating, namely spectral combination, and on bi-grating diffraction imaging that is based on spectral combination. The spectral combination characteristic of a grating is the capability of combining multiple light beams of different wavelengths incident from specific angles into a single beam. The bi-grating diffraction imaging is the formation of the image of an object with two gratings: the first grating disperses the multi-color light beams from the object and the second combines the dispersed light beams to form the image. We gave the conditions necessary for obtaining the spectral combination. We also presented the equations that relate the two gratings’ spatial frequencies, diffraction orders and positions necessary for obtaining the bi-grating diffraction imaging.展开更多
文摘The resonance absorption of a multilayered bi-grating which consists of thin-film corrugated periodically in two directions is investigated. The absorption in a multilayered thin-film bi-grating has been of considerable interest since we can expect more complex behaviors in the absorption phenomen by virtue of the presence of double periodicity and multilayer structure. In solving the problem, we employed a computational technique based on modal expansion. Taking a sandwiched structure /Ag/SiO2/Ag/ for an example, we observed: 1) excitation of a single-interface surface plasmon mode at the lit surface of the 1st Ag layer with strong field enhancement for thick enough Ag layer case;2) excitation of coupled short-range or long-range surface plasmon modes at each surface between vacuum and Ag layers with strong field enhancements for thin enough Ag layer cases no matter with the thickness of SiO2 layers;3) enhancements of field at surfaces between Ag and SiO2 layers in some cases related with the thickness of SiO2 layers. The coupled plasmon modes were resulted by the resonance waves on four surfaces in these cases.
基金Supported by the National Natural Science Foundation of China (Grant No. 10364001)the Natural Science Foundation of Guangxi Province (Grant No. 0043001)
文摘This paper reports on a new property of grating, namely spectral combination, and on bi-grating diffraction imaging that is based on spectral combination. The spectral combination characteristic of a grating is the capability of combining multiple light beams of different wavelengths incident from specific angles into a single beam. The bi-grating diffraction imaging is the formation of the image of an object with two gratings: the first grating disperses the multi-color light beams from the object and the second combines the dispersed light beams to form the image. We gave the conditions necessary for obtaining the spectral combination. We also presented the equations that relate the two gratings’ spatial frequencies, diffraction orders and positions necessary for obtaining the bi-grating diffraction imaging.
