Diamond Based Optical Metasurfaces for Broadband Wavefront Shaping in Harsh Environment

Abstract Metasurface enables a new class of “meta‐optics” that can manipulate light at subwavelength scale. Despite that versatile metasurfaces have been demonstrated based on a wide range of materials, the vulnerability of conventional materials to harsh environments, i.e., low resistance to corrosion, low transparency at short wavelength, and lack of thermal/mechanical stability, greatly limit their applications in extreme conditions. Diamond is well‐known for exceptional properties, including the highest thermal conductivity, high damage resistance, extraordinary hardness, and chemical inertness. Therefore, diamond based metasurface is generally expected to benefit from its material merits for extreme use. However, the performance of diamond metasurface in harsh environments remains unexplored up to date. To address this question, this work is designed to study the suitability of single‐crystal diamond based metasurface for broadband applications under harsh environments. As an example, diamond metasurfaces with representative functionalities, including holographic wavefront‐shaping, DUV‐focusing, are investigated under high‐temperature, acid/alkali, and abrasive conditions, respectively. The findings prove the capability of diamond metasurfaces for applications in broadband and harsh conditions, which not only provides a practical and scalable scheme to encode on‐demand functionalities into diamond, but also unlocks a capable candidate to develop robust, large bandwidth, and durable meta‐optics for advanced wavefront shaping under extreme conditions.