Relation between plasmonic tip emission and electromagnetic enhancement evidenced in tip‐enhanced Raman spectroscopy

The thickness of multifunctional oxide films directly affects the localized enhancement of the electromagnetic field and hence is a key factor for realizing novel photonic or optoelectronic devices. To this end, we theoretically exploit the principle of tip‐enhanced Raman spectroscopy on the surface of multifunctional oxide films (bismuth ferrite and barium titanate) on a gold substrate. An electromagnetic field enhancement of up to 104 in close proximity of the tip apex was obtained. The good agreement between simulation and experiment of spatial resolution of the tip supports the validity of our model. By investigation of surface plasmon polaritons that propagates at the interface between the multifunctional film and the gold substrate, we demonstrated a thickness dependent propagation length and amplitude. This study indicates a critical thickness of the films above which neither a considerable near‐field nor a tip‐mediated excitation are observed. This confirms the validity, promise, and power of tip‐enhanced Raman spectroscopy technique for the analysis of various electro‐optic materials.

Section: Spatial Resolutionsupporting

confidence: 62%

Section: Resultsmentioning

confidence: 74%

Near‐field enhancements and surface plasmon polaritons with multifunctional oxide thin films

Dab

Thomas

Hajlaoui

et al. 2018

“…The TERS mappings demonstrate that the evolution of the Au tip‐enhanced luminescence is strongly correlated with the intensity of the Raman modes from the single‐wall carbon nanotubes and the substrate. They found a very good agreement between all relevant parameters confirming the essential role of the electromagnetic enhancement mechanism in surface enhanced spectroscopy …”

Section: Surface‐enhanced Raman Spectroscopymentioning

confidence: 99%

“…They found a very good agreement between all relevant parameters confirming the essential role of the electromagnetic enhancement mechanism in surface enhanced spectroscopy. [48] 10 | BIOSCIENCES Principal areas of growth in Raman spectroscopy are wide applications involving biological molecules and more recently in biomedical settings, and in particular with micro-Raman imaging. In this section, JRS papers with a central emphasis in the biosciences are described under the general classifications of biomolecules, cells, bacteria and viruses, and biomedical applications.…”

Section: Sers Substratesmentioning

confidence: 99%

Recent advances in linear and nonlinear Raman spectroscopy. Part XII

Nafie

2018

This annual review is an overview of advances in the field of Raman spectroscopy as found in papers published in the previous calendar year in the Journal of Raman Spectroscopy (JRS), as well as in trends over the past decade across journals that have published papers important to the field of Raman spectroscopy. This information is gleaned from statistical data on article counts obtained from the Clarivate Analytic's Web of Science Core Collection by year and by subfield of Raman spectroscopy. Additional information is gleaned from presentations at the XXVI International Conference on Raman Spectroscopy (ICORS 2018) in Jeju Island, Korea in August 2018, and contributions on Raman scattering at SCIX 2018, organized by the Federation of Analytical Chemistry and Spectroscopy Societies (FACSS) in Atlanta, Georgia, USA in October 2018. Coverage is also provided for topics from the European Conference on Nonlinear Optical Spetroscopy (ECONOS 2018) held in April in Milan, Italy and GeoRaman 2018 in Catania, Italy in June. Finally, papers published in JRS in 2017 are highlighted and arranged by topics at the frontier of Raman spectroscopy. On the basis of this survey information, it is clear that Raman spectroscopy continues as in recent years as a rapidly expanding field of research across a wide range of novel disciplines and applications that provide sensitive photonic information of matter at the molecular level.

“…Combining the utility of scanning probe microscopy and Raman scattering, tip‐enhanced Raman spectroscopy (TERS) has become an ultrasensitive detection technique, and it is widely used in the fields of atomic structure, catalytic processes, and the redox behavior of single molecules . The selective Raman enhancement has been studied through the modifications and functionalization of TERS probes and controlling of surface plasmon polarizations and light polarizations .…”

Section: Introductionmentioning

confidence: 99%

Selective excitation of one among the three peaks of tip‐enhanced Raman spectroscopy by a shaped ultrafast laser pulse

Xia

Zhao

Zhang

et al. 2019

There are generally several neighboring Raman peaks that are excited simultaneously in tip‐enhanced Raman spectroscopy (TERS). A method to selectively excite a specific Raman peak and simultaneously depress the others is required for suppressing noise and improving detection sensitivity and accuracy. In this study, we demonstrate a scheme for selective excitation of one Raman peak among three excited states in TERS by properly shaping the pump and Stokes femtosecond laser pulses. The shaped pump and Stokes pulses are transformed into time domain, discretized and reconstructed; they are then used to irradiate the TERS structure obliquely. The impulse responses at five probe points of the TERS structure are calculated followed by a Fourier transform. In these cases, the probability of one selectively excited Raman transition increases by several hundreds to tens of thousands in amplitude, whereas the others are both depressed to zero. The probe points at different positions in the tip apex do not affect the enhanced and selective excitation of one Raman transition among the three excited states.