Flexible all-glass planar structured fabricated by RF-sputtering

^a IFN-CNR, CSMFO Lab. and FBK Photonics Unit, Via alla Cascata 56/C, Povo, 38123 Trento, Italy
^b IFN-CNR, P.zza Leonardo da Vinci 32, 20133 Milan, Italy
^c Chair of Biological Imaging and TranslaTUM, Technische Universität München, Ismaninger Str. 22, D-81675 Munich, Germany
^d Dept. of Physics, Politecnico di Milano, P.zza L. da Vinci 32, 20133 Milan, Italy
^e Dept. of Materials Technology, Faculty of Applied Sciences, Ho Chi Minh City University of Technology and Education, Vo Van Ngan Str. 1, Thu Duc District, 720214 Ho Chi Minh City, Vietnam
^f Center for Sensors and Devices, Micro Nano Facility, Fondazione Bruno Kessler, Via Sommarive 18, Povo, 38123, Trento, Italy
^g Dept. of Mechanics, Materials and Biomedical Engineering, Wroclaw University of Science and Technology, Smoluchowskiego 25, 50-370 Wroclaw, Poland
^h Dept. of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano 77, 38123 Trento, Italy
ⁱ Institute of Low Temperature and Structure Research, PAS, ul. Okólna 2, 50422, Wroclaw, Poland
^l IFAC-CNR, MiPLab, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy, France

^* Corresponding author: alessandro.chiasera@cnr.it

Published online: 13 October 2022

Abstract

Flexible SiO₂/HfO₂ 1D photonic crystals and active SiO₂–HfO₂:Er³⁺ all-glass flexible planar waveguides fabricated by radio frequency sputtering, are presented. The 1D photonic crystals show a strong dependence of the optical features on the light incident angle: i) blue-shift of the stopband and ii) narrowing of the reflectance window. Nevertheless, the most interesting result is the experimental evidence that, even after the 1D photonic crystals breakage, where the flexible glass shows naked-eye visible cracks, the multilayer structures generally maintain their integrity, resulting to be promising systems for flexible photonic applications thanks to their optical, thermal and mechanical stability. The flexible planar waveguides, fabricated on ultrathin flexible glass substrate, showed an attenuation coefficient lower than 0.2 dB/cm at 1.54 μm, and exibits emission in the NIR region, resulting particularly suitable as waveguide amplifier in the C band of telecommunications.