Since the development of diffractive optical elements in the 1970s, researchers have increasingly uncovered sophisticated fundamental principles of optics to replace the existing bulky optical elements with thin and lightweight counterparts. The attempts have recently resulted in nanophotonic metasurfaces that contain flat optics made of dense arrays of metal or semiconductor nanostructures. Such structures can effectively control the local light scattering phase and amplitude based on plasmonic or Mie resonances. Scientists have studied the two types of resonances to realize small-form-factor optics that deliver multifunctionality and control across the light field. While such metasurface functions have remained static, it is highly desirable to achieve dynamic control for emerging photonic applications such as light direction and ranging (LIDAR) for 3-dimensional (3-D) mapping. Plasmonic and Mie resonances only offer weak electrical tunability, but decades of research on optical modulation describe exciton manipulation to be stronger to control optical properties of a material.
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Source: Phys.org