Optical Trapping of Nanoparticles Through Artificially-Engineered Flat Materials

Day to day advancements in technology requires new materials and new technologies to be developed. Researchers nowadays are focused towards developing compact, portable, efficient, and, on-chip realizable devices that are easy to fabricate. Metamaterials have proved to be useful for the development of such devices due to their compactness and on-chip realization as compared to the bulky optical instruments. They have found their applications in almost every field of science and technology. In this paper, we have demonstrated the design of an optical tweezer that is capable of trapping nanoparticles in the visible regime. Hydrogenated amorphous silicon (a-Si:H) is used as the basic building block of this metalens along with glass as the substrate. Due to its ability to trap particles in the visible domain and its ease of manufacturing, it can be replaced in many commercial applications such as cameras, microscopes, and other devices that require high-resolution imaging. For the simulation of this metalens full-wave solution of Finite Difference Time Domain solutions is used, and optical force calculations are performed using Maxwell Stress Tensor technique. The proposed design could prove to be the foundation stone towards the development of highly compact, efficient, and commercially realizable on-chip devices.