A new technology that can allow for better light control without requiring large, difficult-to-integrate materials and structures has been developed. The photonic integrated chip could allow for many advances in the optical field and industry, ranging from improvements in virtual-reality glasses to optical remote sensing.
Traditionally, scientists have had two options when it comes to controlling light for use in various optical devices. The first is a photonic integrated circuit (PIC) that can be incorporated onto small chips but has limited ability to control free-space light — light propagating in air, outer space, or a vacuum, as opposed to being guided in fibers or other waveguides. The second is a newly emergent metasurface — an artificially engineered thin layer that allows for light manipulation at subwavelength scale but cannot be integrated on a chip.
Researchers solved this problem by incorporating the best qualities of the two previous options into a new, hybrid photonic architecture that has metasurfaces integrated onto a PIC chip while maintaining high light controllability. Incorporation of the PICs and metasurfaces makes it possible to drive the metasurfaces using guided waves inside the PICs. It enables routing of light among different metasurfaces, performing multiple complex functions on a single chip.
This new development could have applications in optical communications, optical remote sensing, free-space optical interconnects, and virtual reality and augmented reality displays. The hybrid system has the advantages of both the metasurfaces and the PICs. In addition, the design is highly flexible and modular. A library of the building blocks can be established for reusing and creating consistent functional components across various devices or systems.