Quantifying Remote Heating from Propagating Surface Plasmon Polaritons

Abstract

We report a method to electrically detect heating from excitation of propagating surface plasmon polaritons (SPP). The coupling between SPP and a continuous wave laser beam is realized through lithographically defined gratings in the electrodes of thin film gold "bow tie" nanodevices. The propagating SPPs allow remote coupling of optical energy into a nanowire constriction. Heating of the constriction is detectable through changes in the device conductance and contains contributions from both thermal diffusion of heat generated at the grating and heat generated locally at the constriction by plasmon dissipation. We quantify these contributions through computational modeling and demonstrate that the propagation of SPPs provides the dominant contribution. Coupling optical energy into the constriction via propagating SPPs in this geometry produces an inferred temperature rise of the constriction a factor of 60 smaller than would take place if optical energy were introduced via directly illuminating the constriction. The grating approach provides a path for remote excitation of nanoconstrictions using SPPs for measurements that usually require direct laser illumination, such as surface-enhanced Raman spectroscopy.

Photovoltages and hot electrons in plasmonic nanogaps

“…A detailed study of the magnitude of the conductance change as a function of the distance between the grating and the nanowire center, including computational electrodynamics and thermal transport calculations, has been reported elsewhere. 15 That study demonstrates that, with 2 µm oxide under the devices, the SPPs readily reach the nanowire from gratings more than 10 µm away.…”

Fast quantitative optical detection of heat dissipation by surface plasmon polaritons

“…The gratings are chosen to compensate the momentum mismatch between the SPPs and the exciting photons with wavelength λ = 785 nm. 27,37 The setup used for our experiments is shown in Fig. 1(b) and consists of an optical microscope to measure the optical transmissivity of the Si membranes with a high spatial resolution and a pulsed light emitting diode for illumination.…”

“…[23][24][25][26] Localised surface plasmons as well as propagating surface plasmon polaritons (SPPs) [27][28][29][30][31] represent coupled charge and field effects, and their influence on the optical and charge transport properties has been studied. [32][33][34][35][36][37] However, in most cases, the heat transport that goes along with the propagation of SPPs with finite lifetime has been ignored, mainly because of lack of experimental access, although it might have a major impact on the interpretation of nano-optoelectronic experiments. Recently, indirect detection schemes based on conductance changes of atomic contacts and nano-constrictions have been implemented to infer local temperature changes.…”

“…Recently, indirect detection schemes based on conductance changes of atomic contacts and nano-constrictions have been implemented to infer local temperature changes. 36,37 While these methods have a high spatial resolution, they are time consuming and require a complex calibration for each individual contact under study. To understand the nano-and mesoscale impact of SPPs it is mandatory to study the heat contribution by direct local thermometry, and in equilibrium between the electronic and phononic system, such that a local temperature is well defined.…”

Localized and Propagated Surface Plasmons in Metal Nanoparticles and Nanowires

“…Silver nanowires usually act as plasmonic waveguides with lateral size of 200−300 nm and axial length up to 10 μm, exhibiting many interesting applications. For example, plasmonic interference [26], waveparticle duality [27], remote excitation of Raman scattering [28][29][30], long-distance plasmonic gain [31][32][33], broadside nano-antennas [34], etc. It is impossible to introduce every result on plasmonics in this short chapter.…”