scholarly journals Raman scattering in high-refractive-index nanostructures

Nanophotonics ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Søren Raza ◽  
Anders Kristensen

AbstractThe advent of resonant dielectric nanomaterials has provided a new path for concentrating and manipulating light on the nanoscale. Such high-refractive-index materials support a diverse set of low-loss optical resonances, including Mie resonances, anapole states, and bound states in the continuum. Through these resonances, high-refractive-index materials can be used to engineer the optical near field, both inside and outside the nanostructures, which opens up new opportunities for Raman spectroscopy. In this review, we discuss the impact of high-refractive-index nano-optics on Raman spectroscopy. In particular, we consider the intrinsic Raman enhancement produced by different dielectric resonances and their theoretical description. Using the optical reciprocity theorem, we derive an expression which links the Raman enhancement to the enhancement of the stored electric energy. We also address recent results on surface-enhanced Raman spectroscopy based on high-refractive-index dielectric materials along with applications in stimulated Raman scattering and nanothermometry. Finally, we discuss the potential of Raman spectroscopy as a tool for detecting the optical near-fields produced by dielectric resonances, complementing reflection and transmission measurements.

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 518
Author(s):  
Margherita Longoni ◽  
Maria Sole Zalaffi ◽  
Lavinia de Ferri ◽  
Angela Maria Stortini ◽  
Giulio Pojana ◽  
...  

The electrochemical preparation of arrays of copper ultramicrowires (CuUWs) by using porous membranes as templates is critically revisited, with the goal of obtaining cheap but efficient substrates for surface enhanced Raman spectroscopy (SERS). The role of the materials used for the electrodeposition is examined, comparing membranes of anodized aluminum oxide (AAO) vs. track-etched polycarbonate (PC) as well as copper vs. glassy carbon (GC) as electrode material. A voltammetric study performed on bare electrodes and potentiostatic tests on membrane coated electrodes allowed the optimization of the deposition parameters. The final arrays of CuUWs were obtained by chemical etching of the template, with NaOH for AAO and CH2Cl2 for PC. After total etching of the template, SERS spectra were recorded on CuUWs using benzenethiol as SERS probe with known spectral features. The CuUW substrates displayed good SERS properties, providing enhancement factor in the 103–104 range. Finally, it was demonstrated that higher Raman enhancement can be achieved when CuUWs are decorated with silver nanostars, supporting the formation of SERS active hot-spots at the bimetallic interface.


2017 ◽  
Vol 8 ◽  
pp. 2492-2503 ◽  
Author(s):  
Somi Kang ◽  
Sean E Lehman ◽  
Matthew V Schulmerich ◽  
An-Phong Le ◽  
Tae-woo Lee ◽  
...  

Herein we describe the fabrication and characterization of Ag and Au bimetallic plasmonic crystals as a system that exhibits improved capabilities for quantitative, bulk refractive index (RI) sensing and surface-enhanced Raman spectroscopy (SERS) as compared to monometallic plasmonic crystals of similar form. The sensing optics, which are bimetallic plasmonic crystals consisting of sequential nanoscale layers of Ag coated by Au, are chemically stable and useful for quantitative, multispectral, refractive index and spectroscopic chemical sensing. Compared to previously reported homometallic devices, the results presented herein illustrate improvements in performance that stem from the distinctive plasmonic features and strong localized electric fields produced by the Ag and Au layers, which are optimized in terms of metal thickness and geometric features. Finite-difference time-domain (FDTD) simulations theoretically verify the nature of the multimode plasmonic resonances generated by the devices and allow for a better understanding of the enhancements in multispectral refractive index and SERS-based sensing. Taken together, these results demonstrate a robust and potentially useful new platform for chemical/spectroscopic sensing.


2015 ◽  
Vol 51 (33) ◽  
pp. 7152-7155 ◽  
Author(s):  
O. O. Alabi ◽  
A. N. F. Edilbi ◽  
C. Brolly ◽  
D. Muirhead ◽  
J. Parnell ◽  
...  

Surface enhanced Raman spectroscopy using a gold substrate and excitation at 514 nm can detect sub parts per million quantities of asphaltene and thereby petroleum.


The Analyst ◽  
2014 ◽  
Vol 139 (13) ◽  
pp. 3352-3355 ◽  
Author(s):  
Michael Driver ◽  
Yue Li ◽  
Jinkai Zheng ◽  
Eric Decker ◽  
David Julian McClements ◽  
...  

A simple fabrication method for preparing lipophilic gold nanoparticles (AuNPs) suitable for use as substrates in surface-enhanced Raman scattering (SERS) applications of lipids was developed.


2021 ◽  
Author(s):  
Zhaoyi Chen ◽  
Ke Feng ◽  
Zhibin Chen ◽  
Jinxing Shen ◽  
Huanliang Li

Abstract In this study, we reported a silver sinusoidal nanograting used in microchannels, forming H2O/Ag/NOA heterostructure, and studied the impact of interactions of grating-coupled surface Plasmon polaritons (SPPs) on Surface-enhanced Raman Scattering (SERS). FDTD simulations showed that when the refractive index of NOA is close to that of H2O, there were two modes of odd coupling and even coupling between SPPs. Additionally, the thinner the Ag grating, the stronger the coupling, accompanied by the frequency shift of the two coupling modes. We also estimated the influence of refractive index of the surrounding medium on SPPs coupling by varying the dielectric of the upper and lower layer of Ag grating. Our experimental results were supported by FDTD calculations, which confirmed the importance of the interactions of grating-coupled SPPs in the design of SERS substrate.


Author(s):  
Vadim Elyutin ◽  
◽  
Muhammad A. Butt ◽  
Svetlana N. Khonina ◽  
◽  
...  

Sign in / Sign up

Export Citation Format

Share Document