Direction-Selective Energy Control Using Thermal Lens

Abstract

Directional energy control is a critical requirement for applications involving adaptive thermal management, infrared (IR) signature suppression, and multiband optical modulation. Herein, a directional energy control surface (DECS) is introduced that achieves passive, refraction-based directional energy manipulation across visible and IR bands without requiring external power input. The DECS comprises three key layers: The directional control layer (DCL), composed of a thermal lens array, facilitates direction-selective refraction, enabling real-time control over radiative signatures. The IR control layer (IRCL), featuring an Au/quartz pattern, modulates IR emissivity. Finally, the visible coloration layer (VCL) enables adjustable optical reflection in the visible band. Experiments demonstrate that the DECS enables periodic, direction-selective modulation of thermal and optical signatures, enhancing or suppressing radiance effectively depending on the detection angle. Extending the experimental evaluation to 3D wedge geometries confirms that the DECS can maintain its directional control capability in complex environments. These results establish the DECS as a scalable and energy-efficient solution for directional energy control across multibands, offering a new paradigm for passive spectral and angular energy regulation. Thus, this study can facilitate the development of next-generation energy-controlling surfaces with potential applications in thermal camouflage, radiative cooling, energy-efficient coatings, and dynamic optical management.

Keywords: directional energy control; direction‐selective; multispectral energy modulation; refraction‐based energy control; thermal lens array.