Nonlinear Optical Signal Generation Mediated by a Plasmonic Azimuthally Chirped Grating

Abstract

Plasmonic gratings are simple and effective platforms for nonlinear signal generation since they provide a well-defined momentum for photon–plasmon coupling and local hot spots for frequency conversion. Here, a plasmonic azimuthally chirped grating (ACG), which provides spatially resolved broadband momentum for photon–plasmon coupling, was exploited to investigate the plasmonic enhancement effect in two nonlinear optical processes, namely two-photon photoluminescence (TPPL) and second harmonic generation (SHG). The spatial distributions of the nonlinear signals were determined experimentally by hyperspectral mapping with ultrashort pulsed excitation. The experimental spatial distributions of nonlinear signals agree very well with the analytical prediction based on photon–plasmon coupling with the momentum of the ACG, revealing the “antenna” function of the grating in plasmonic nonlinear signal generation. This work highlights the importance of the antenna effect of the gratings for nonlinear signal generation and provides insight into the enhancement mechanism of plasmonic gratings in addition to local hot spot engineering.

Deformation induced evolution of plasmonic responses in polymer grafted nanoparticle thin films

“…Recent studies indicate that the tunable optical properties of plasmonic nanoparticle assemblies make them attractive for applications in sensing, 28–31 energy conversion, 10,32 non-linear signal enhancement, 33,34 plasmon-enhanced catalysis, 35 opto-electronic devices 36,37 and theranostics. 10,38 The optical properties in such assemblies depends on the building blocks and their spatial organization.…”

“…24 The intensity of LSPR depends strongly on the shape, size, and spatial arrangement of the nanoparticles, as well as the dielectric function (or refractive index) of the background. 23,[25][26][27] Recent studies indicate that the tunable optical properties of plasmonic nanoparticle assemblies make them attractive for applications in sensing, [28][29][30][31] energy conversion, 10,32 non-linear signal enhancement, 33,34 plasmon-enhanced catalysis, 35 optoelectronic devices 36,37 and theranostics. 10,38 The optical properties in such assemblies depends on the building blocks and their spatial organization.…”

Broadband Four‐Wave Mixing Enhanced by Plasmonic Surface Lattice Resonance and Localized Surface Plasmon Resonance in an Azimuthally Chirped Grating

“…In our previous studies, the ACG works in the regime, where its optical response can be well described analytically by considering only the periodicity. [25][26][27][28] We showed that the ACG could be designed to have grating sections simultaneously supporting photon-to-surface plasmon polaritons (SPP) coupling at various frequencies relevant for the nonlinear optical processes. The suitable sector areas of the ACG could be predicted solely by considering the photon-SPP momentum-matching condition.…”