Adiabatic nanofocusing: spectroscopy, transport and imaging investigation of the nano world

Abstract

Adiabatic compression plays a fundamental role in the realization of localized enhanced electromagnetic field hot spots, it provides the possibility to focus at nanoscale optical excitation. It differs from the well-known lightning rod effect since it is based on the lossless propagation of surface plasmon polaritons (SPPs) up to a nano-sized metal tip where the energy density is largely enhanced. Here we discuss two important applications of adiabatic compression: Raman and hot electron spectroscopy at nanometric resolution. The underlying phenomena are the conversion of SPPs into photons or hot electrons. New scanning probe spectroscopy techniques along with experimental results are discussed. We foresee that these techniques will play a key role in relating the functional and structural properties of matter at the nanoscale.

Hot Electron Nanoscopy and Spectroscopy (HENs)

“…is method is weakly sensitive to wavelength spreading, resulting in being weakly affected by the broad spectrum of the light source. Simulations on this kind of structure indicate a substantial preservation of the laser pulse after propagation along a 10-μm gold cone [33] and that this coupling efficiency can be extremely effective, even approaching 90% [71].…”

“…(a-c) Reproduced with permission from [37], copyright OSA 2011. (d-g) Reproduced with permission from [33], copyright IOP 2014. scanning electron microscopy (SEM) image of a PhC example. In this case, the material was silicon with a refractive index n 633nm = 3.917 + i 0.0122. e periodicity was P = 290 nm with hole radius R = 0.4*P and slab thickness z 0 = 162 nm.…”

“…Details about the experimental setup and the current to voltage I-V characterization of an Au/n-type GaAs nanojunction can be found in Refs [14,33]. Here, we briefly recall the experimental setup architecture: we modulate the amplitude of the laser light while scanning in contact mode, as shown in Figures 15.10 and 15.13, measuring simultaneously the tip-sample current.…”

“…(a) Reproduced with permission from[32], copyright NPG 2010. (c) Reproduced with permission from[33], copyright IOP 2014.…”

О Фокусировке Поверхностных Плазмонных Волн На Свободной Поверхности Металлической Пленки

“…Кроме указанного приложения острийной нанофокусировки к рамановской спектроскопии поверхности, развиваются также и другие приложения, например, связанные с генерацией в сильном оптическом поле фокуса (на нановершине) горячих электронов и оптического излучения при столкновении этих электронов с исследуемой поверхностью (hot electron spectroscopy) [2]. Предлагается использовать указанное явление для поверхностного картирования полупроводниковых наноструктур [3].…”