Broadband thermal imaging using meta-optics

• DOI: 10.1038/s41467-024-45904-w
• Publication Date: 2024-02-23T11:03:02Z
• Authors: Luocheng Huang; Zheyi Han; Anna Wirth-Singh; Vishwanath Saragadam; Saswata Mukherjee; Johannes E. Fröch; Quentin A. A. Tanguy; Joshua Rollag; Ricky Gibson; Joshua R. Hendric...; Philip W. C. Hon; Orrin Kigner; Zachary Coppens; Karl F. Böhringer; Ashok Veeraraghavan; Arka Majumdar
• Keywords: 0301 basic medicine; 03 medical and health sciences; Science; Q; FOS: Physical sciences; 78A10; Physics - Applied Physics; Applied Physics (physics.app-ph); Article; Physics - Optics; Optics (physics.optics)

AbstractSubwavelength diffractive optics known as meta-optics have demonstrated the potential to significantly miniaturize imaging systems. However, despite impressive demonstrations, most meta-optical imaging systems suffer from strong chromatic aberrations, limiting their utilities. Here, we employ inverse-design to create broadband meta-optics operating in the long-wave infrared (LWIR) regime (8-12 μm). Via a deep-learning assisted multi-scale differentiable framework that links meta-atoms to the phase, we maximize the wavelength-averaged volume under the modulation transfer function (MTF) surface of the meta-optics. Our design framework merges local phase-engineering via meta-atoms and global engineering of the scatterer within a single pipeline. We corroborate our design by fabricating and experimentally characterizing all-silicon LWIR meta-optics. Our engineered meta-optic is complemented by a simple computational backend that dramatically improves the quality of the captured image. We experimentally demonstrate a six-fold improvement of the wavelength-averaged Strehl ratio over the traditional hyperboloid metalens for broadband imaging.