Sol-Gel Photonic Glasses: From Material to Application.

In this review, we present a short overview of the development of sol-gel glasses for application in the field of photonics, with a focus on some of the most interesting results obtained by our group and collaborators in that area. Our main attention is devoted to silicate glasses of different compositions, which are characterized by specific optical and spectroscopic properties for various applications, ranging from luminescent systems to light-confining structures and memristors. In particular, the roles of rare-earth doping, matrix composition, the densification process and the fabrication protocol on the structural, optical and spectroscopic properties of the developed photonic systems are discussed through appropriate examples.

Photonic Crystal Stimuli-Responsive Chromatic Sensors: A Short Review.

Photonic crystals (PhC) are spatially ordered structures with lattice parameters comparable to the wavelength of propagating light. Their geometrical and refractive index features lead to an energy band structure for photons, which may allow or forbid the propagation of electromagnetic waves in a limited frequency range. These unique properties have attracted much attention for both theoretical and applied research.

Glassy Microspheres for Energy Applications.

Microspheres made of glass, polymer, or crystal material have been largely used in many application areas, extending from paints to lubricants, to cosmetics, biomedicine, optics and photonics, just to mention a few. Here the focus is on the applications of glassy microspheres in the field of energy, namely covering issues related to their use in solar cells, in hydrogen storage, in nuclear fusion, but also as high-temperature insulators or proppants for shale oil and gas recovery. An overview is provided of the fabrication techniques of bulk and hollow microspheres, as well as of the excellent results made possible by the peculiar properties of microspheres.