Diamond Metasurface-Based Optical Tweezers With Enhanced Robustness.

Optical tweezers have revolutionized the manipulation of micro- and nano-scale particles, with impacts across biophysics, materials science, and quantum optics. However, their miniaturization for lab-on-a-chip applications is hindered by bulky optical components. While metasurface-based optical tweezers offer an ultracompact alternative, they suffer from laser-induced thermal effects, which degrade their performance, stability, and durability. Here, we overcome this challenge with diamond metasurfaces, leveraging the material's exceptional thermal conductivity, low thermal expansion, and high optical damage threshold to ensure structural integrity under high-power illumination. We experimentally demonstrate versatile particle manipulations using diamond metasurface optical tweezers, including 2D trapping, precise translocation, and controlled rotation via angular momentum transfer. This work not only resolves the critical thermal limitations of conventional metasurface optical tweezers but also establishes a robust platform for high-power, miniaturized optomechanical systems, paving the way for their scalable integration into demanding photonic applications.