Full text loading...
Sketch of a plasmonic lens under (a) normal and (b) inclined illumination. (c),(d) top view of (a) and (b), respectively. (c) The focus (black dot) of the plasmonic lens is the center of the circle under normal illumination. (d) The focus (point B) of the plasmonic lens shifts away from the center under inclined illumination. The amount of shifted distance depends on the size of the plasmonic lens and the incident angle .
(a)–(c) MWS simulation of the electrical field intensity distributions of a plasmonic lens with different incident angles and incident polarizations. The diameter of the simulated plasmonic lens is . The excitation wavelength is in a vacuum. (a) Normal incident with polarization; (b) incident angle with polarization; (c) incident angle with polarization; (d) A schematic illustration of light focusing by a conventional optical lens.
Fluorescence images observed by optical microscope under different incident angles and polarizations. (a) Normal incident with horizontal polarization; (b) incident angle with horizontal polarization; (c),(d) incident angle with horizontal and vertical polarization, respectively. The polarization directions are indicated by the double-side white arrows. The incident direction is upwards.
Fluorescence images observed by optical microscope for two different plasmonic lenses (diameter: 10 and 1, respectively) using exactly the same illumination configuration. The excitation light incident angle is . The polarization directions are indicated by the double-side white arrows.
Article metrics loading...