Long-range surface plasmons on gold-coated single-mode fibers

Abstract

A standard single-mode optical fiber, coated with low-index polymer (Cytop), then a thin Au sheath, immersed in fluid, is proposed as a structure for optical (bio)chemical sensing. The highest-order EH 1m cladding modes are found to couple strongly to long-or short-range surface plasmons on the Au sheath, forming coupled modes that are sensitive to the refractive index of the fluid or to a biochemical adlayer formed on the outer surface of the Au sheath. Interrogation of the modes can be achieved with the help of a tilted grating photoinduced into the core of the fiber. We demonstrate experimentally, in this manner, the excitation of these modes, and their use for bulk sensing. Furthermore, negative bulk sensitivity was observed for some leaky modes beyond cutoff.

Surface plasmon excitation at near-infrared wavelengths in polymer optical fibers

“…And with the recent progress made in the photo-inscription of high-quality gratings in such POFs [18], SPR excitation could be further envisaged in these fibers. It could even lead to long-range SPR excitation as a result of a matching of the refractive indices between the fiber and the surrounding medium, as recently demonstrated in [19]. Fig.…”

High Resolution NIR TFBG-Assisted Biochemical Sensors

“…In this configuration, long-range SPPs can be excited, which in principle could lead to narrower resonances. Preliminary results with this configuration showed a sensitivity of 115 nm/RIU [52]. And with a different approach towards the realization of fiber-based long-range-SPR sensing has been proposed inside a hollow fiber.…”

Transmission spectrum alteration of a silica fiber taper while covering lateral surface with heterostructure of ZnTe/Bi2Te3 thin film

“…In computation, we used this straightforward method [22], which at given complex, electric and magnetic susceptibilities of the layers allows to determine parameters of any mode-field in the fiber (including a leaky mode) with an arbitrarily prescribed accuracy [26]. We have successfully tested our method by applying it to the problems, already solved via alternative computation methods [27], and then comparing the results obtained [28].…”