SHINE · Multiphoton lithography and advanced materials engineering for the generation of shaped single and multispectral emission at the nanoscale

Focused femtosecond laser radiation enables the direct fabrication of nanoscale 3D structures from photosensitive materials, with sub-diffraction feature sizes. This approach, known as multiphoton lithography (MPL), has emerged as a versatile laser-based additive manufacturing method, offering maskless, highly flexible, and fully 3D structuring capabilities across diverse research fields. Interestingly, MPL is no longer limited to polymer-based architectures. Recent advances have extended its scope to optically active structures, particularly emitting light in the visible range, opening opportunities for creating compact and complex photonic architectures that align with the ongoing drive toward system miniaturization and would allow advancing light–matter interactions. However, shaping the emission of such active structures by MPL still faces intrinsic limitations primary found in MPL’s resolution and optical properties of printed structures. The SHINE project aims to address these limitations by combining advanced material engineering, MPL, and a post-annealing step. This strategy will allow the realization of active 3D nanostructures with high resolution, by doping hybrid materials with single or multiple rare-earth ions (REIs), followed by annealing to form crystalline high-refractive-index (> 2) environments for efficient REI emission in the visible spectrum. Building on this, SHINE will explore shaped emission through the 3D nanostructures that will address chiroptical properties, to directly generate circularly polarized emission (CPE). Beyond this approach, MPL’s 3D printing capabilities will be harnessed to integrate optical elements with the active 3D nanostructures, to couple the spin angular momentum of REI emission to its orbital angular momentum. This active 3D system will allow direct generation and manipulation of single and multispectral CPE, paving the way for multidimensional beam shaping and new opportunities in spin-orbit photonics.