Mapping the near fields of plasmonic nanoantennas by scattering-type scanning near-field optical microscopy

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F15%3APU118807" target="_blank" >RIV/00216305:26620/15:PU118807 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1002/lpor.201500031" target="_blank" >http://dx.doi.org/10.1002/lpor.201500031</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/lpor.201500031" target="_blank" >10.1002/lpor.201500031</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Mapping the near fields of plasmonic nanoantennas by scattering-type scanning near-field optical microscopy

Popis výsledku v původním jazyce

Near-field optical microscopy techniques provide information on the amplitude and phase of local fields in samples of interest in nanooptics. However, the information on the near field is typically obtained by converting it into propagating far fields where the signal is detected. This is the case, for instance, in polarization-resolved scattering-type scanning near-field optical microscopy (s-SNOM), where a sharp dielectric tip scatters the local near field off the antenna to the far field. Up to now, basic models have interpreted S- and P-polarized maps obtained in s-SNOM as directly proportional to the in-plane (inline image or inline image) and out-of-plane (inline image) near-field components of the antenna, respectively, at the position of the probing tip. Here, a novel model that includes the multiple-scattering process of the probing tip and the nanoantenna is developed, with use of the reciprocity theorem of electromagnetism. This novel theoretical framework provides new insights into the interpretation of s-SNOM near-field maps: the model reveals that the fields detected by polarization-resolved interferometric s-SNOM do not correlate with a single component of the local near field, but rather with a complex combination of the different local near-field components at each point (inline image, inline image and inline image). Furthermore, depending on the detection scheme (S- or P-polarization), a different scaling of the scattered fields as a function of the local near-field enhancement is obtained. The theoretical findings are corroborated by s-SNOM experiments which map the near field of linear and gap plasmonic antennas. This new interpretation of nanoantenna s-SNOM maps as a complex-valued combination of vectorial local near fields is crucial to correctly understand scattering-type near-field microscopy measurements as well as to interpret the signals obtained in field-enhanced spectroscopy.

Název v anglickém jazyce

Mapping the near fields of plasmonic nanoantennas by scattering-type scanning near-field optical microscopy

Popis výsledku anglicky

Near-field optical microscopy techniques provide information on the amplitude and phase of local fields in samples of interest in nanooptics. However, the information on the near field is typically obtained by converting it into propagating far fields where the signal is detected. This is the case, for instance, in polarization-resolved scattering-type scanning near-field optical microscopy (s-SNOM), where a sharp dielectric tip scatters the local near field off the antenna to the far field. Up to now, basic models have interpreted S- and P-polarized maps obtained in s-SNOM as directly proportional to the in-plane (inline image or inline image) and out-of-plane (inline image) near-field components of the antenna, respectively, at the position of the probing tip. Here, a novel model that includes the multiple-scattering process of the probing tip and the nanoantenna is developed, with use of the reciprocity theorem of electromagnetism. This novel theoretical framework provides new insights into the interpretation of s-SNOM near-field maps: the model reveals that the fields detected by polarization-resolved interferometric s-SNOM do not correlate with a single component of the local near field, but rather with a complex combination of the different local near-field components at each point (inline image, inline image and inline image). Furthermore, depending on the detection scheme (S- or P-polarization), a different scaling of the scattered fields as a function of the local near-field enhancement is obtained. The theoretical findings are corroborated by s-SNOM experiments which map the near field of linear and gap plasmonic antennas. This new interpretation of nanoantenna s-SNOM maps as a complex-valued combination of vectorial local near fields is crucial to correctly understand scattering-type near-field microscopy measurements as well as to interpret the signals obtained in field-enhanced spectroscopy.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

<a href="/cs/project/ED1.1.00%2F02.0068" target="_blank" >ED1.1.00/02.0068: CEITEC - central european institute of technology</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2015

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Laser and Photonics Reviews

ISSN

1863-8880

e-ISSN

1863-8899

Svazek periodika

9

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

13

Strana od-do

237-249

Kód UT WoS článku

000368255200006

EID výsledku v databázi Scopus

2-s2.0-84957957242