Experimental demonstration of CMOS-compatible long-range dielectric-loaded surface plasmon-polariton waveguides (LR-DLSPPWs)

Abstract

We demonstrate the design, fabrication and experimental characterization of long-range dielectric-loaded surface plasmon-polariton waveguides (LR-DLSPPWs) that are compatible with complementary metal-oxide semiconductor (CMOS) technology. The demonstrated waveguide configuration represents a silicon nitride ridge atop a thin strip of metal, which is positioned on a partially oxidized layer of silicon supported by a silicon oxide layer. The demonstrated waveguides feature reasonable mode confinement (~0.5μm2) and show rather long propagation (~700 μm) at telecom wavelengths. Owing to the existence of a metal strip within the structure, one can envision the co-propagation of electrical and photonic signals within the structure, enabling thereby seamless integration of photonic and electronic circuits. Electrical signals in metal strips supporting plasmonic modes can be used for variety of applications, e.g. to control the propagation of radiation via the thermo-optic effect.

Active Nanophotonic Circuitry Based on Dielectric‐loaded Plasmonic Waveguides

“…[ 174,175 ] Well-defi ned propagation of the long-range DLSPPW mode with confi nement approximately 1 μm and even below was observed at telecom wavelengths (Figures 21 b,c). [ 176,177 ] The propagation length of the mode was about 0.5 mm (affected by the leakage due to a fi nite thickness of the dielectric layer and the fabrication imperfections), while the theoretical estimation for the potential propagation length is about 3 mm. An efficient transmission of the mode through a waveguide S-bend was demonstrated with just ≈1.8 dB loss for the waveguide separation of 10 μm and the S-bend horizontal length of 20 μm (Figure 21 b,c).…”

Transparent conducting oxides for electro-optical plasmonic modulators

“…Among them, a waveguide is the key passive component connecting all elements in the circuit. Various designs of plasmonic waveguides have been proposed, aiming to achieve the highest mode localization while maintaining reasonable propagation losses [42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58]. However, because of the high intrinsic losses of plasmonic materials, signal propagation is highly damped even for the best (with the highest DC conductivity) metals such as silver and gold.…”

Ultra-thin films for plasmonics: a technology overview

“…Generally, for plasmonic experiments, an aluminium film deposited by an e-beam or thermal evaporation is above 20 nm in thickness [82]. One certain plasmonic application of an ultrathin Al layer for guiding hybrid long-ranged SPPs was reported in [83]. The thickness of the layer deposited by evaporation was 15 nm.…”