Dynamic visible-infrared transmittance regulation based on fluoroaluminate glass by femtosecond-laser-customized induced microstructure

Abstract

Herein, we report significant microstructure-induced dynamic visible–infrared transmittance regulation on a novel fluoroaluminate glass (AlF3) via femtosecond-laser-customized fabrication technology. Fluoroaluminate glass, which has excellent optical transmittance in the visible–infrared wavelength range (400–5000 nm), is a candidate for visible and infrared optical devices. Based on its performance, three types of microstructures or material transitions (Snow-Layer Microstructure (SLS), Surface-Ablation Microstructure (SAS), and Interior-Modified Microstructure (IMS)) were successfully achieved using a femtosecond-laser-customized microstructure, including surface and interior fabrication routes with cylindrical lens focusing. Dynamic and reversible structural transition features were observed between the snow-layer and surface-ablation microstructures. These types of structures showed different transmittance regulation trends at visible and infrared wavelengths. The transmittance is decreased for IMS, SAS, and SLS in the visible region, while in the infrared region the transmittance increased for IMS and decreased for SAS and SLS. Based on Raman spectroscopy analyses, the chemical structures of the SAS before and after femtosecond-laser ablation appeared to remain constant, whereas the SLS showed a significant difference, giving rise to different transmittance regulations. This study provides a novel fabrication method and strategy for regulating visible and infrared transmission and promotes smart application of glass materials.