Conference Agenda

High-aspect-ratio semiconductor nanostructures are relevant optical materials. Knowledge of their mechanical properties is key in view of any application. We probe individual MoS₂ nanotubes and InAs nanowires using ultrafast all-optical photoacoustic microscopy, a non-contact technique with picosecond temporal and sub-micrometre spatial resolution. We observe elastic eigenmodes in the tens of GHz range and analyze their dependence on structural parameters, providing insight into elastic properties and acoustic attenuation. This approach establishes ultrafast optical spectro-microscopy as a powerful tool for nanoscale metrology and nanomechanics.

Laser-Induced Forward Transfer (LIFT) has emerged as a versatile and widely used technique for the precise deposition of functional materials, enabling applications ranging from microelectronics to photonics and bioengineering. However, its potential to directly generate ordered sub-wavelength structures during the transfer process has not been reported so far. In this work, LIFT is applied to sol–gel TiO₂ thin films containing silver nanoparticles to locally deposit nanocomposite thin films on a receiver substrate. Under specific fluence and pulse accumulation conditions, the transferred material forms regular submicron gratings resulting from a self-organization process occurring on the receiver during the transfer process. Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) characterizations allow to characterize the evolution of the film thickness, grating period and shape and to propose a description of the underlying mechanisms leading to the grating formation. These results reveal an unexpected route for large-scale self-organization of periodic patterns during LIFT and direct deposition of functional nanocomposite materials on various kinds of surfaces.

We present a hydrogel platform for fast, high-resolution surface morphing using light. Surfaces can be controlled with up to 2 Hz frequency and features generated with sub-micron precision. The platform is capable of micro-object trans-portation via dual illumination and can be extended to passive, humidity sensitive surface structures, and free-standing films for active laser beam steering.

Solid-state plasmonic lattice lasers based on Al nanoparticles arranged in a triangular lattice were designed and nanofabricated via Electron Beam Lithography. The gain medium is a thin polymeric layer of PMMA doped with a dye emitting at about 600 nm. The coupling between the surface lattice mode and the dye emission was studied to optimize lasing efficiency as a function of nanoparticle size, PMMA thickness, and dye concentration.

A smooth Silicon–air interface exhibits significant Fresnel reflection, resulting in approximately 30% transmission loss at THz wavelengths. Previously reported Silicon meta-structures for anti-reflection are mostly in the low THz spectral range. In this work, we demonstrate subwavelength Silicon gratings fabricated by laser machining and blade dicing that effectively suppress Fresnel reflections, increasing the transmittance per interface from the nominal 70% to 93% at 5.7 THz.