Demonstration of long-range surface plasmon-polariton waveguide sensors with asymmetric double-electrode structures

Abstract

We demonstrate a long-range surface plasmon-polaritons (LRSPP) refractive-index sensor using an asymmetric double-electrode LRSPP waveguide configuration. The LRSPP sensor is inherently self-referencing by virtue of two Bragg wavelengths in the transmission spectrum generated by a Bragg grating. The measured sensitivity is about 130 nm/RIU and 27 pm/K, which means a sensing resolution of ∼10−6 RIU and a temperature determination with an inaccuracy of 0.04 K under measurement accuracy of the Bragg wavelength of 1 pm. The sensor dimensions of 1.95 mm in total length and submicrometer in fluidic-channel thickness may be desirable for highly integrated sensors based on LRSPP.

Theoretical biosensing performance of surface plasmon polariton Bragg gratings

“…The study was concerned with the propagation of the LRSPP along a structure This thesis work can be considered as an extension of the Jettè thesis, since the periodic step in width design is adopted to conduct the study, following the same approach presented by Jettè. LRSPP based sensors with a Bragg gratings structure were proposed and investigated in [36,37], but the structure was completely different than the structure adopted for this thesis. In reference [37], LRSPPs are supported by an asymmetric double electrode structure consisting of a metal slab with a Bragg grating layer topped with a finite width metal stripe, containing a microfluidic channel in between, and bounded by dielectric as claddings, as in Figure 8.…”

“…LRSPP based sensors with a Bragg gratings structure were proposed and investigated in [36,37], but the structure was completely different than the structure adopted for this thesis. In reference [37], LRSPPs are supported by an asymmetric double electrode structure consisting of a metal slab with a Bragg grating layer topped with a finite width metal stripe, containing a microfluidic channel in between, and bounded by dielectric as claddings, as in Figure 8. The mode is confined by the metal stripe and slab.…”

“…Schematic of asymmetric double electrode structure with Bragg gratings with cross sectional view. "Reprinted with permission from[37]. Copyright 2010, AIP Publishing LLC.…”

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

“…LRSPPs are less confined and less surface sensitive but their attenuation can be one to three orders of magnitude lower, depending on the structure, leading to significantly longer optical interaction lengths, or narrower resonances under wavelength interrogation, which ultimately produces a sensor with greater transducer (overall sensitivity [11]. Indeed, LRSPPs have been successfully used in several biosensing demonstrations in prism-coupled [12][13][14][15][16] and waveguide geometries [17][18][19][20].…”

Surface sensitivity of straight long-range surface plasmon waveguides for attenuation-based biosensing

“…Cytop (Asahi) and Teflon (Dupont) are the most commonly used low-index cladding materials. Cytop and Teflon have both been used to support LRSPPs on metal slabs or grating structures in sensing experiments [4][5][6][7][8][9].…”