The mid-wave infrared (MWIR) is an important band for numerous applications ranging from night vision to biochemical sensing. However, unlike visible or near-infrared (NIR) optical parts, which are economically available off the shelf, MWIR optics are plagued by much higher costs and often inferior performance compared to their visible or NIR counterparts. Optical metasurfaces, artificial materials with subwavelength-scale thicknesses and on-demand electromagnetic responses, provide a promising solution for cost-effective, high-performance infrared optics. Using high-refractive-index (> 5) chalcogenide materials deposited on IR-transparent substrates, we have experimentally demonstrated a MWIR transmissive metasurface device with diffraction-limited focusing and imaging performance and optical efficiency up to 75%. We further show that the metasurface design can accommodate ultra-wide field-of-view and the fabrication method can be extended to conformal integration of metasurface optics on curved surfaces. The projected size, weight and power advantages, coupled with the manufacturing scalability leveraging standard microfabrication technologies, makes the meta-optical devices promising for next-generation MWIR system applications.
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