Large area infrared wideband flexible extinction film

Abstract With the improvement of precision in modern optical systems, the demand for the ability to eliminate stray light in the system is also increasing. However, traditional methods for eliminating stray light either utilize complex mechanical structures and black coatings, or reduce the emission of stray light through refrigeration, which hinders the miniaturization and lightweighting of the system, especially in infrared systems. To address this challenge, we demonstrate a large-area infrared broadband flexible extinction film designed with an ultra-thin structure, which can achieve 97.1% absorption in 3-5μm atmospheric windows, with a total film thickness not exceeding λ/6. This device achieves broadband absorption with a simple structure, enabling it to be integrated on large-area flexible substrates. It demonstrates excellent extinction performance, feasibility and repeatability of large-area processing, and can be applied in fields such as eliminating stray light, infrared stealth, and electromagnetic shielding.