We study the sensing properties of an intensity-modulated fiber-optic surface plasmon resonance （SPR） sensor using radially polarized beam （RPB）. Because of the rotational symmetry of fiber and RPB, surface plasmo...We study the sensing properties of an intensity-modulated fiber-optic surface plasmon resonance （SPR） sensor using radially polarized beam （RPB）. Because of the rotational symmetry of fiber and RPB, surface plasmon can be excited more efficiently at the sensor surface, which results in an obvious improvement of the sensitivity. Our experiments demonstrate that the sensitivity in the case of RPB illumination is three times higher than that of linearlv polarized beam illumination.展开更多
Light propagation through a metal/nonlinear dielectric material/metal（M-NL-M） structure is numerically studied.The design parameters of the M-NL-M structure are found with the waveguide theory so that the structure ...Light propagation through a metal/nonlinear dielectric material/metal（M-NL-M） structure is numerically studied.The design parameters of the M-NL-M structure are found with the waveguide theory so that the structure only supports the symmetric surface plasmon polaritons（SPP（0）） mode and the antisymmetric surface plasmon polaritons（SPP（1）） mode.The coupling between the two modes within the M-NL-M structure is exploited.Through controlling the propagation constants of the two modes with the intensity-dependent dielectric constant of the nonlinear Kerr material,an effective all-optical control of plasmonic signal modulator can be realized with this M-NL-M structure.展开更多
A vectorial optical field generator(VOF-Gen) based on two reflective phase-only liquid crystal spatial light modulators enables the creation of an arbitrary optical complex field. In this work, the capabilities of the...A vectorial optical field generator(VOF-Gen) based on two reflective phase-only liquid crystal spatial light modulators enables the creation of an arbitrary optical complex field. In this work, the capabilities of the VOF-Gen in terms of manipulating the spatial distributions of phase, amplitude, and polarization are experimentally demonstrated by generating a radially polarized optical field consisted of five annular rings, the focusing properties of which are also numerically studied with vectorial diffraction theory. By carefully adjusting the relative amplitude and phase between the adjacent rings, an optical needle field with purely longitudinal polarization can be produced in the focal region of a high numerical aperture lens. The versatile method presented in this work can be easily extended to the generation of a vectorial optical field with any desired complex distributions.展开更多
Plasmonic field enhancement in a fully coated dielectric near field scanning optical microscope （NSOM） probe under radial polarization illumination is analyzed using an axially symmetric three-dimensional （3D） fin...Plasmonic field enhancement in a fully coated dielectric near field scanning optical microscope （NSOM） probe under radial polarization illumination is analyzed using an axially symmetric three-dimensional （3D） finite element method （FEM） model. The enhancement factor strongly depends on the illumination spot size, taper angle of the probe, and the metal film thickness. The tolerance of the alignment angle is investigated. Probe designs with different metal coatings and their enhancement performance are studied as well. The nanometric spot size at the tip apex and high field enhancement of the apertureless NSOM展开更多
基金supported by the National Basic Research Program of China (No.2006cb302905)the Key Program of National Natural Science Foundation of China (No.60736037)+1 种基金the National Natural Science Foundation of China (No.10704070)P.Wang was also supported by the Science and Technological Fund of Anhui Province for Outstanding Youth (No.08040106805)
文摘We study the sensing properties of an intensity-modulated fiber-optic surface plasmon resonance （SPR） sensor using radially polarized beam （RPB）. Because of the rotational symmetry of fiber and RPB, surface plasmon can be excited more efficiently at the sensor surface, which results in an obvious improvement of the sensitivity. Our experiments demonstrate that the sensitivity in the case of RPB illumination is three times higher than that of linearlv polarized beam illumination.
基金supported by the National Key Basic Research Program of China(No.2006CB302905)the Key Program of National Natural Science Foundation of China(No.60736037)+1 种基金the National Natural Science Foundation of China(Nos.10704070 and 60977019)the Science and Technological Fund of Anhui Province for Outstanding Youth(No.08040106805).
文摘Light propagation through a metal/nonlinear dielectric material/metal（M-NL-M） structure is numerically studied.The design parameters of the M-NL-M structure are found with the waveguide theory so that the structure only supports the symmetric surface plasmon polaritons（SPP（0）） mode and the antisymmetric surface plasmon polaritons（SPP（1）） mode.The coupling between the two modes within the M-NL-M structure is exploited.Through controlling the propagation constants of the two modes with the intensity-dependent dielectric constant of the nonlinear Kerr material,an effective all-optical control of plasmonic signal modulator can be realized with this M-NL-M structure.
文摘A vectorial optical field generator(VOF-Gen) based on two reflective phase-only liquid crystal spatial light modulators enables the creation of an arbitrary optical complex field. In this work, the capabilities of the VOF-Gen in terms of manipulating the spatial distributions of phase, amplitude, and polarization are experimentally demonstrated by generating a radially polarized optical field consisted of five annular rings, the focusing properties of which are also numerically studied with vectorial diffraction theory. By carefully adjusting the relative amplitude and phase between the adjacent rings, an optical needle field with purely longitudinal polarization can be produced in the focal region of a high numerical aperture lens. The versatile method presented in this work can be easily extended to the generation of a vectorial optical field with any desired complex distributions.
基金Weibin Chen is supported by the Dayton Area Gradu-ate Studies Institute(DAGSI)Research Fellowship.
文摘Plasmonic field enhancement in a fully coated dielectric near field scanning optical microscope （NSOM） probe under radial polarization illumination is analyzed using an axially symmetric three-dimensional （3D） finite element method （FEM） model. The enhancement factor strongly depends on the illumination spot size, taper angle of the probe, and the metal film thickness. The tolerance of the alignment angle is investigated. Probe designs with different metal coatings and their enhancement performance are studied as well. The nanometric spot size at the tip apex and high field enhancement of the apertureless NSOM
