Broadband Transparent AlF3–ZnF2-based composite glass controllably synthesized for photonic application

This paper reports a novel AlF3–ZnF2-based composite glass (AZCG) containing an AlF3 single-crystal phase. The AZCGs were prepared by phase-separation engineering technology. The prepared AZCGs exhibit excellent comprehensive properties including high transmittance from 0.2 µm to 7.4 µm, low phonon energy (601 cm−1), high hardness (394 Hv), excellent chemical stability, high service temperature (280 °C), and low emissivity. In addition, an Er-doped AZCG shows comparable luminescence properties to a ZrF4-based glass. The samples exhibit large emission cross-sections (1.7×10−20 cm2) and long lifetimes (6.5 ms @ 2.7 µm). Consequently, the AZCG material has potential applications in various fields such as infrared windows, infrared imaging, and host materials.