Photo-thermal modulation of surface plasmon polariton propagation at telecommunication wavelengths

Abstract

We report on photo-thermal modulation of thin film surface plasmon polaritons (SPP) excited at telecom wavelengths and traveling at a gold/air interface. By operating a modulated continuous-wave or a Q-switched nanosecond pump laser, we investigate the photo-thermally induced modulation of SPP propagation mediated by the temperature-dependent ohmic losses in the gold film. We use a fiber-to-fiber characterization set-up to measure accurately the modulation depth of the SPP signal under photo-thermal excitation. On the basis of these measurements, we extract the thermo-plasmonic coefficient of the SPP mode defined as the temperature derivative of the SPP damping constant. Next, we introduce a figure of merit which is relevant to characterize the impact of temperature onto the properties of bounded or weakly leaky SPP modes supported by a given metal at a given wavelength. By combining our measurements with tabulated values of the temperature-dependent imaginary part of gold dielectric function, we compute the thermo-optical coefficients (TOC) of gold at telecom wavelengths. Finally, we investigate a pulsed photo-thermal excitation of the SPP in the nanosecond regime. The experimental SPP depth of modulation obtained in this situation are found to be in fair agreement with the modulation depths computed by using our values of gold TOC.

Spectroscopic Observation of Calcium‐Induced Reorientation of Cellobiose Dehydrogenase Immobilized on Electrodes and its Effect on Electrocatalytic Activity

“…Propagating waves of oscillating electrons that occur at the interface between a metal and a dielectric, known as surface plasmon polaritons (SPPs), have attracted great interest in the field of optoelectronics 5 and may help provide a crucial enabling link for optoelectronics 6, 7 since they bridge the gap between nanoscale electronic and ∼micron‐scale optics. Plasmon propagation can be modulated via the dielectric’s optical properties: previous investigators have explored SPP switches using photochromic 8, p‐n junction 9, electrooptical 10–13, magneto‐optical 14, or thermo‐optical 15, 16 control. SPPs have also been extensively exploited in sensing applications 17–20, as the SPP dispersion serves as an indicator of pH or local (near the SPP‐supporting interface) electrochemical conditions.…”

Plasmonic Heating in Au Nanowires at Low Temperatures: The Role of Thermal Boundary Resistance

“…8 Plasmon-driven heating has been extensively studied at room temperature and successfully utilized for targeted thermal treatment of cancer tumors, 9 driving chemical reactions, 10 and control of the material temperature with nanoscale localization. [11][12][13][14] Local plasmon-driven temperature variation has also been proposed as an essential driver of photo-induced changes in local electrostatic potential. 15 At low temperatures the optical properties of plasmonic nanostructures could be strongly dependent on local temperature, which could be used as an efficient control parameter.…”

Heterogeneous plasmonic trimers for enhanced nonlinear optical absorption

“…Pulsed laser excitation of metallic nanostructures produces an abrupt temperature rise inside the nanostructures, giving rise to several photothermal, and optoacoustic phenomena that can be used in bubble formation, 1-3 selective cell targeting, 4,5 catalytic reactions, 6,7 optoacoustic imaging, 8 nano-welding, 9,10 and thermally induced optical modulation and limiting. [11][12][13] In the case of the latter applications, plasmon-enhanced light absorption induces a large temperature change which causes a large modification of the dielectric function, resulting in thermally induced nonlinear absorption and scattering. To optimize these processes in plasmonic structures, one must balance the thermo-optic coefficients of all materials involved, the magnitude of the heat generation, and its spatial distribution throughout the nanostructure.…”