Bloch Long-Range Surface Plasmon Polaritons on Metal Stripe Waveguides on a Multilayer Substrate

Abstract

We propose and demonstrate a thin Au stripe on a truncated 1D dielectric photonic crystal covered with Cytop as a waveguide for Bloch long-range surface plasmon polaritons. High-quality mode outputs were observed and a mode power attenuation of 12–17 dB/mm measured at λ0 = 1310 nm for propagation in the plane of the truncated photonic crystal and within its stopband. The truncated 1D photonic crystal advantageously enables the use of a large range of materials for the substrate, breaking free from the constraint of material symmetry to support long-range plasmons. An input grating coupler implemented as a periodic array of nanoscale Au ridges on a Au stripe was used to excite the mode via perpendicularly incident p-polarized light. The output was provided by adding a second grating coupler near the end of a waveguide to diffract light upward or by polishing the output facet and allowing the mode to radiate into a free-space beam. Advantageously, grating coupling eliminates the need for high-quality end facets, and optical alignment is simplified. Given its practicality, the structure proposed is of strong interest for biosensing.

Electrochemical Performance of Lithographically-Defined Micro-Electrodes for Integration and Device Applications

“…Small, closely spaced metallic features of dimensions and separation in the micrometer range are of interest in electrochemical device applications or for integration with optical biosensors, e.g., based on surface plasmon-polaritons (SPPs) [1][2][3]. Optical biosensors exploiting long-range surface plasmon-polariton (LRSPP) waveguides have solicited significant interest because they enable compactness in integrated architectures, and offer very high sensitivity in an arrayed format [4][5][6][7]. LRSPPs are supported by a thin metal slab or stripe bounded by dielectrics of similar refractive index [8].…”

“…For biosensing, the metal stripe is typically formed of Au and is supported by a cladding of low refractive index, e.g., a fluoropolymer such as Cytop, which has an index close to water and is thus well-matched to the index of aqueous biosensing media [5,6]. Alternatively, Au-sensing waveguides can be fabricated on a multilayer dielectric cladding, behaving optically as a 1-D photonic crystal (1DPC), and supporting Bloch LRSPPs within the bandgap of the 1DPC [4,5,7]. Advantageously, the multilayer cladding in such structures can be formed of robust inorganic dielectrics (e.g., SiO 2 , Si 3 N 4 , Ta 2 O 5 ), allowing multiple wafer-scale processing steps to be applied thereon, thereby enabling a high degree of integration and conferring strength and resilience to the chips [7].…”

Electrical Excitation of Long-Range Surface Plasmons in PC/OLED Structure with Two Metal Nanolayers

“…A multilayer structure in the form [PC/M/air] has been proposed to simplify the implementation of LRSP in practical applications, where the external dielectric is air [14]. This approach was tested with diverse systems, including thin palladium layers (for ultrasensitive hydrogen detection [15][16][17]), thin gold layers in blue spectral range (for nitrogen dioxide detection [18]), and thin ferromagnetic cobalt layers (for magnetoplasmonics [19]), among others (see also [20][21][22][23] for examples of other applications).…”

Дисперсия Объемных Волн В Структуре "Графен--Диэлектрик--Графен"

“…Волновые характеристики поверхностных и объемных ПП во многом определяются характером дисперсии материальных параметров граничащих сред. Поведение ПП в металлодиэлектрических волноводных структурах и возможность их практического применения достаточно подробно рассматривались в работах [3,[5][6][7]. Однако использование в качестве волноведущего слоя металлических пленок неизбежно приводит к существенным потерям и значительному уменьшению длины пробега ПП.…”