The optical properties of regular nanoparticle arrays consisting of spherical semiconductor and noble metal nanoparticles
are providing interesting aspects for the development of novel and powerful sensor concepts. In this contribution, we
demonstrate femtosecond laser-induced transfer of metallic and semiconductor thin films as a unique tool for realizing
controllable structures of any desired configuration of exactly spherical nanoparticles, having diameters between 40 nm
and 1500 nm. The optical properties of nanoparticles and nanoparticle arrays fabricated by this new approach are
investigated spectroscopically and by scattering of surface plasmon-polaritons (SPPs). SPP-scattering constitutes a novel
method to obtain insight into the contribution of different multipole moments to the scattering properties of the particles.
Furthermore, the particles can be combined with 3D photonic structures fabricated using two-photon polymerization,
providing new approaches to the development of nanophotonic devices and 3D metamaterials. Here, we demonstrate an
optical sensor with a sensitivity of 365 nm/RIU and a figure of merit of 21.5 in the visible spectral range.
We study the guiding properties of laser-written dielectric-loaded surface plasmon polariton waveguides
(DLSPPWs). The guiding structures such as straight waveguides, S-bends, Y-splitter, resonant filters, and Mach-
Zehnder interferometers are realized by two-photon induced polymerization of commercial photolithographic
resists. The height of the components can be adjusted by spin-coating of the material. Minimum widths of 400
nm of the DLSPPWs fabricated directly on thin metal films can be achieved. Replica molding of polymer
surface structures allows a further reduction of the DLSPPW width down to 200 nm. The DLSPPWs are
characterized by leakage radiation microscopy in the visible and near infrared spectral region. We demonstrate
the possibility to selectively excite different modes in the waveguides. Fourier-plane imaging allows a direct
observation of the excited modes of the DLSPPWs. The simultaneous excitation of fundamental and higherorder
modes results in a mode-beating, providing the possibility to control the splitting ratio of guided SPPs in
Y-splitters. The experimental results are supported by theoretical modelling using the finite-difference time
domain method.
We study both, theoretically and experimentally the light-to-surface plasmon polariton (SPP) and SPP-to-SPP scattering
using the Green's function method and leakage radiation microscopy. The scattering structures are fabricated by
nonlinear lithography and laser induced transfer (LIT). SPPs are exited on dot- and ridge-like surface structures. We
demonstrate symmetric or asymmetric excitation of SPP beams and show that the SPP excitation efficiency strongly
depends on the component of the excitation field perpendicular to the metal surface. By adjusting the angle of the
incident beam to the maximum of the total electric field component perpendicular to the metal surface, the scattering
efficiency of light on a single nanoparticle into SPPs can be increased by a factor of 200. The SPP beams allow studying
scattering properties of perfectly spherical gold particles with diameters between 200 nm and 1600 nm fabricated by LIT
of liquid gold droplets. For these diameters, the description of scattering of electromagnetic waves with optical
frequencies has to take into account higher-order terms. Leakage radiation microscopy provides the unique possibility to
observe scattering features attributed to magnetic dipole and electric quadrupole contributions in the 2D scattering
patterns of SPPs. The results are supported by numerical modelling using the Green's tensor approach.
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