We explore the excitation of plasmons in 3D plasmon crystal metamaterials and report the observation of a delocalized plasmon mode, which provides extremely high spectral sensitivity (>2600 nm per refractive index unit (RIU) change), outperforming all plasmonic counterparts excited in 2D nanoscale geometries, as well as a prominent phase-sensitive response (>3*104 deg. of phase per RIU). Combined with a large surface for bioimmobilization provided by the 3D matrix, the proposed sensor architecture promises a new important landmark in the advancement of plasmonic biosensing technology.

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A three-dimensional (3D) holographic focal volume engineering method is proposed and employed for advanced multiphoton polymerization. A large number of foci are closely positioned in space according to a designed geometry, avoiding undesired interference effects by phase engineering. Through all-optical micro-displacements in space, the discrete foci bundle leads to the realization of complete 3D arbitrary structures. The microstructures are fabricated by direct laser writing without additional optical or mechanical motion support. We report a 20-times faster fabrication time in comparison to point-by-point laser polymerization techniques.

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geometries ensure large surface area interaction of photonic devices with the surrounding medium. Here, we demonstrate that metamaterials composed of 3D metallic Split Cube Resonator (SCR) elements assembled in various arrangements enable resonantly enhanced refractive index sensing. The proper arrangement of the SCR elements results in almost perfect narrow-band direction-selective absorption, which is highly sensitive to the refractive index of the surrounding environment. The experimental sensitivity achieved exceeds 5.5 μm per Refractive Index Unit (RIU) with theoretical predictions showing that this can reach 11 μm/RIU. The structures allow easy fabrication via direct laser writing and highly selective electroless metal plating. Thus, the proposed metadevices are ideal candidates for assisting cost-effective infrared polarization-resolved sensing and direction-selective spectral filtering in and out of the infrared atmospheric transparency window.

We demonstrate that paraxial ring-Airy beams can approach the wavelength limit, while observing a counterintuitive, strong enhancement of their focal peak intensity. Using numerical simulations, we show that this behavior is a result of the coherent constructive action of paraxial and nonparaxial energy flow. A simple theoretical model enables us to predict the parameter range over which this is possible.

We present our research into the fabrication of fully three-dimensional metallic nanostructures using diffusion-assisted direct laser writing, a technique which employs quencher diffusion to fabricate structures with resolution beyond the diffraction limit. We have made dielectric 3D nanostructures by multiphoton polymerization using a metal-binding organic-inorganic hybrid material, and we covered them with silver using selective electroless plating. We have used this method to make spirals and woodpiles with 600 nm intralayer periodicity. The resulting photonic nanostructures have a smooth metallic surface and exhibit well-defined diffraction spectra, indicating good fabrication quality and internal periodicity. In addition, we have made dielectric woodpile structures decorated with gold nanoparticles. Our results show that diffusion-assisted direct laser writing and selective electroless plating can be combined to form a viable route for the fabrication of 3D dielectric and metallic photonic nanostructures.

We report the spectral shaping of supercontinuum generation in liquids by employing properly engineered Bessel beams coupled with artificial neural networks. We demonstrate that given a custom spectrum, neural networks are capable of outputting the experimental parameters needed to generate it experimentally.