Interfering Plasmons in Coupled Nanoresonators to Boost Light Localization and SERS

AbstractWe delineate the four principal surface plasmon polariton coupling and interaction mechanisms in subwavelength gratings, and demonstrate their significant roles in shaping the optical response of plasmonic gratings. Within the framework of width-graded metal–insulator-metal nano-gratings, electromagnetic field confinement and wave guiding result in multiwavelength light localization provided conditions of adiabatic mode transformation are satisfied. The field is enhanced further through fine tuning of the groove-width (w), groove-depth (L) and groove-to-groove-separation (d). By juxtaposing the resonance modes of width-graded and non-graded gratings and defining the adiabaticity condition, we demonstrate the criticality of w and d in achieving adiabatic mode transformation among the grooves. We observe that the resonant wavelength of a graded grating corresponds to the properties of a single groove when the grooves are adiabatically coupled. We show that L plays an important function in defining the span of localized wavelengths. Specifically, we show that multiwavelength resonant modes with intensity enhancement exceeding three orders of magnitude are possible with w < 30 nm and 300 nm < d < 900 nm for a range of fixed values of L. This study presents a novel paradigm of deep-subwavelength adiabatically-coupled width-graded gratings—illustrating its versatility in design, hence its viability for applications ranging from surface enhanced Raman spectroscopy to multispectral imaging.

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Small footprint optoelectrodes using ring resonators for passive light localization

Microsystems & Nanoengineering ◽

10.1038/s41378-021-00263-0 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Vittorino Lanzio ◽

Gregory Telian ◽

Alexander Koshelev ◽

Paolo Micheletti ◽

Gianni Presti ◽

...

Keyword(s):

State Of The Art ◽

Three Dimensional ◽

Network Activity ◽

Ring Resonators ◽

Spatiotemporal Resolution ◽

Optical Ring Resonators ◽

Light Localization ◽

Order Of Magnitude ◽

Small Footprint

AbstractThe combination of electrophysiology and optogenetics enables the exploration of how the brain operates down to a single neuron and its network activity. Neural probes are in vivo invasive devices that integrate sensors and stimulation sites to record and manipulate neuronal activity with high spatiotemporal resolution. State-of-the-art probes are limited by tradeoffs involving their lateral dimension, number of sensors, and ability to access independent stimulation sites. Here, we realize a highly scalable probe that features three-dimensional integration of small-footprint arrays of sensors and nanophotonic circuits to scale the density of sensors per cross-section by one order of magnitude with respect to state-of-the-art devices. For the first time, we overcome the spatial limit of the nanophotonic circuit by coupling only one waveguide to numerous optical ring resonators as passive nanophotonic switches. With this strategy, we achieve accurate on-demand light localization while avoiding spatially demanding bundles of waveguides and demonstrate the feasibility with a proof-of-concept device and its scalability towards high-resolution and low-damage neural optoelectrodes.

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Controlling Light Localization and Light-Matter Interactions with Nanoplasmonics

Small ◽

10.1002/smll.201001044 ◽

2010 ◽

Vol 6 (22) ◽

pp. 2498-2507 ◽

Cited By ~ 128

Author(s):

Vincenzo Giannini ◽

Antonio I. Fernández-Domínguez ◽

Yannick Sonnefraud ◽

Tyler Roschuk ◽

Roberto Fernández-García ◽

...

Keyword(s):

Light Localization

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Analytical theory of light localization in one-dimensional disordered photonic crystals

Solid State Communications ◽

10.1016/j.ssc.2013.01.009 ◽

2013 ◽

Vol 158 ◽

pp. 38-45 ◽

Cited By ~ 2

Author(s):

A.A. Greshnov ◽

M.A. Kaliteevski ◽

R.A. Abram

Keyword(s):

Photonic Crystals ◽

Analytical Theory ◽

One Dimensional ◽

Light Localization

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Tunable laser induced periodic surface structures in Ge2Sb2Te5 thin films

Journal of Physics Conference Series ◽

10.1088/1742-6596/2086/1/012170 ◽

2021 ◽

Vol 2086 (1) ◽

pp. 012170

Author(s):

Irina G Bessonova ◽

Pavel I Trofimov ◽

Petr I Lazarenko ◽

Demid A Kirilenko ◽

Nikolay A Bert ◽

...

Keyword(s):

Thin Films ◽

Phase Change ◽

Low Cost ◽

Beam Steering ◽

Tunable Laser ◽

Surface Structures ◽

Periodic Surface ◽

Light Localization ◽

Rapid Fabrication ◽

Direct Laser

Abstract Planar photonic structures, such as gratings and metasurfaces, are routinely used for beam steering, waveguide coupling, and light localization. However, conventional fabrication techniques that involve lithography are demanding in terms of time and cost. Much cheaper and simpler methods for surface patterning and formation of periodic surface structures are enabled by direct laser processing. Here, we demonstrate low-cost rapid fabrication of high-quality phase gratings based on the formation of laser induced periodic surface structures (LIPSS, or ripples) in Ge2Sb2Te5 (GST) thin films. Due to unique phase change properties of GST, the structures demonstrate strong modulation of refractive index with period controlled by the wavelength of laser irradiation. We study the formation of phase change LIPSS in a broad range of excitation wavelengths and observe transition between regimes with different orientations of generated ripples with respect to laser polarization.

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Light Localization and Stimulated Emission in InGaN/GaN Nanocolumns

Physics Procedia ◽

10.1016/j.phpro.2015.10.012 ◽

2015 ◽

Vol 76 ◽

pp. 68-72

Author(s):

Y. Inose ◽

H. Ueda ◽

N. Shimosako ◽

K. Ema ◽

Y. Igawa ◽

...

Keyword(s):

Stimulated Emission ◽

Light Localization

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