Surface plasmon waveguide coupling

Surface Plasmon Waveguide Coupling in Optical Fibers.212... 

This type of surface resonance can be obtained with a resonator which combines both the long-range surface plasmon and coupled plasmon-waveguide resonators into one device. The resulting resonance spectra are similar in shape and intensity to those obtained with CPWR devices. 

Lavers C.R., Wilkinson J.S., A waveguide-coupled surface plasmon sensor for an aqueous environment, Sens. andActuat. B 1994 22 75-81. 

Fig. 1 (a) Schematic representation of waveguide mode-surface plasmon coupling via k-vector match into a hybrid mode, (b) Experimental scheme of a planar waveguide with a small gold spot on its surface for transmission experiments... 

Fig. 2 Waveguide mode-surface plasmon coupling in fiber geometry with an area of removed cladding and a gold deposition therein, a) Experimental scheme for a single wavelength transmission experiment under controlled coupling angle a into the fiber, b) Experimental scheme for a spectral transmission experiment...

Fig. 3 Experimental scheme for a hollow optical fiber carrying a Bragg grating and a gold layer on the inner surface of the hollow fiber for waveguide mode-surface plasmon coupling and detection in transmission...

Weisser M, Menges B, Mittler-Neher S (1999) Refractive index and thickness determination of monolayers by multi mode waveguide coupled surface plasmons. Sensors Actuators B Chem 56 189-197... 

Keywords Microarray DNA microarray Carbohydrate microarray Protein microarray Antibody microarray G protein-coupled receptor microarray Cellular microarray Optical biosensor Resonant waveguide grating biosensor Surface plasmon resonance Dynamic mass redistribution... 

Abstract Optical detection continues to dominate detection methods in microfluidics due to its noninvasive nature, easy coupling, rapid response, and high sensitivity. In this review, we summarize two aspects of recent developments in optical detection methods on microfluidic chips. The first aspect is free-space (off-chip) detection on the microchip, in which the conventional absorption, fluorescence, chemiluminescence, surface plasmon resonance, and surface enhanced Raman spectroscopies are involved. The second aspect is the optofluidic (inside-chip) detection. Various miniaturized optical components integrated on the microfluidic chip, such as waveguide, microlens, laser, and detectors are outlined. 

Fig. 5 Coupling schemes of incident light to surface plasmons (a) prism coupling, (b) experimental setup for the fiber-optic SPR microsensor, (c) waveguide coupling (Reprinted from [83] with permission of Elsevier), and (d) grating coupling...

Another example of a planar waveguide supporting surface plasmons is a thin metal film sandwiched between two semi-infinite dielectric media (Fig. 7). If the metal film is much thicker than the penetration depth of a surface plasmon at each metal-dielectric interface, this waveguide supports two TM modes, which correspond to two surface plasmons at the opposite boundaries of the metal film. When the metal thickness decreases, coupling between the two surface plasmons occurs, giving rise to mixed modes of electromagnetic field. 

The modes of a dielectric-metal-dielectric waveguide can be found by solving the eigenvalue (Eq. 35). Numerical solutions of this eigenvalue equation for a symmetric waveguide structure ( di = d2) are shown in Fig. 8. For any thickness of the metal film, there are two coupled surface plasmons, which are referred as to the symmetric and antisymmetric surface plasmons. 

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