The sol-gel technique is a very flexible, relatively simple, and low-cost method to fabricate many different innovative photonic structures characterized by specific functionalities. During synthesis, starting from the molecular level, compounds or composites with well controlled composition can be obtained as thin films, powders or monoliths. These materials can be used to prepare such structures as waveguides, photonic crystals, coatings, and bulk glasses including spheres, rings and other geometries exploited in optical resonators fabri- cation. This article presents some results obtained by the authors in the field of the sol-gelderived photonic structures. To emphasise the scientific and technological interest in this kind of systems and the versatility of the sol-gel route, the glass-based nano and micrometer scale range systems are discussed. Particularly, the following systems are described: silica-hafnia glass and glass-ceramic planar waveguides, nanosized tetraphosphates, and silica colloidal crystals. The attention is focused on the spectroscopic properties of Er 3+ -activated materials that due to the light emission can be used in the integrated optics area covering application in sensing, biomedical diagnostic, energy conversion, telecommunication, lighting, and photon management.

Abstract. (70-x)SiO 2 -30HfO 2 -хP 2 O 5 (х= 5, 10 mol %) glass planar waveguides activated by 0.5 mol% Er 3+ ions were prepared by sol-gel route. Several phosphorous precursors have been investigated for the synthesis of a dielectric stable sol useful for the realization of planar waveguides. The waveguides were investigated by different diagnostic techniques. The optical properties such as refractive index, thickness, number of propagating modes and attenuation coefficient were measured at 632.8 and 543.5 nm by prism coupling technique. Transmission measurements were carried out in order to assess the transparency of the deposited films. Photoluminescence measurements and lifetime decay curves of the Er 3+ transition ( 4 I 13/2 → 4 I 15/2 ) were performed in order to investigate the role of P 2 O 5 .

No abstract

No abstract