Broadband and Athermal Infrared Engineering: A Minimalist Meta‐Composite Optical Architecture for a 100°C Temperature Span

Abstract

ABSTRACT Hybrid meta‐refractive systems offer a viable pathway to overcome the multi‐dimensional performance trade‐offs of metalenses. However, conventional spatial‐stacking designs struggle to simultaneously achieve minimalism and athermalization. Here, a minimalist meta‐composite optical architecture is proposed based on a full‐field inverse‐design method. By integrating two‐dimensional subwavelength meta‐atoms onto micro‐curved surfaces, this approach precisely regulates the thermal phase response, achieving significant suppression of both thermal and high‐order aberrations. Based on this, we further demonstrate a meta‐composite optical system (MCOS) comprising only two elements, achieving a focal shift of merely ±6.7 µm across the 8–12 µm bandwidth and a 100°C temperature span (from −40°C to 60°C). Meanwhile, the MCOS exhibits a superior modulation transfer function (MTF) and excellent imaging resolution under various temperature conditions. In addition, the athermalization mechanism and the tolerances of non‐ideal structural profiles for meta‐atoms are rigorously derived and analyzed, effectively mitigating temperature‐induced degradation of image quality. By integrating with an unmanned aerial vehicle (UAV) platform, the excellent infrared thermal imaging demonstration of the MCOS has been experimentally confirmed. This work offers a feasible pathway for the development of integrated optics and the deployment of minimalist optical systems.