Zero-angle incident surface plasmon resonance optical coupling super lens

Abstract

The invention discloses a zero-angle incident surface plasmon resonance (SPR) optical coupling super lens. The super lens comprises three optical faces including a special optical non-spherical face with the surface appearance same as that of the super lens, a fixed-height cylindrical face and a round optical plane. The coupling lens is symmetric about the axis in the normal direction in the center of the optical plane, and the cross section parallel to the optical plane of the lens is round. The coupling lens is made from a high-refractive-index material, and parallel light is emitted into the lens from one side of the optical non-spherical face in the direction parallel to the optical axis, refracted from the special optical non-spherical face and focused at the surface geometric center of the round optical plane of the lens. When the optical plane of the coupling lens is plated with a surface plasmon resonance metal material, zero-angle incidence parallel to the optical axis of the lens can be achieved, and surface plasmons can be excited at the geometric center of the round optical plane of the lens. The coupling super lens effectively avoids the problems that large-angle incidence of a SPR prism coupling system is complex in triangular mechanical structure, large in aberration, low in detection precision and the like.

Description

technical field [0001] The invention relates to the field of optical technology, in particular to a zero-angle incident surface plasmon optical coupling superlens. Background technique [0002] Surface plasmon (Surface Plasmon Resonance, SPR) is a kind of surface electromagnetic wave propagating on the interface between metal and dielectric. The electric field intensity at the metal / dielectric interface is the largest and decays exponentially in the normal direction perpendicular to the interface. The wave vector of the surface plasmon wave is larger than the light wave vector under vacuum conditions, so it is usually necessary to use other means to match the wave vector to excite the SPR. The commonly used coupling methods include prism coupling, waveguide coupling, and grating coupling. In the prism coupling system, since the SPR can only be excited at a specific incident angle, the triangular mechanical structure is widely used to match the excitation angle of the SPR and...

AI Technical Summary

Problems solved by technology

In the prism coupling system, since the SPR can only be excited at a specific incident angle, the triangular mechanical structure is widely used to match the excitation angle of the SPR and the detection of the reflected light after the prism, that is, the illumination optical path and the detection optical path are both At an angle to the normal, the mechanical structure of the entire system is complex and difficult to implement. The prism is not an ideal imaging optical component, resulting in large aberrations, high requirements for opto-mechanical control, and high cost of SPR instruments. , and is difficult to be compatible with conventional optical characterization techniques mostly using normal zero angle incidence

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