Compact On-Chip Metalens-Assisted Optical Switch Enabling Efficient and Scalable Beam Switching.

We propose and demonstrate an integrated optical switch that leverages an optical phased array (OPA) and an on-chip metalens, highlighting its potential for efficient and scalable beam switching across multiple ports within a compact footprint. The device consists of an input multimode interference (MMI) coupler, a phase modulator (PM) array, a beam-transformation region featuring an on-chip metalens layer, and a tapered waveguide array serving as the output ports. The PM array, engineered to effectively manipulate multiple phases for a waveguide array using a single voltage, utilizes metal strips of varying lengths to streamline operation. The on-chip metalens, characterized by varying slot lengths, facilitates the wavefront manipulation of the fast Fourier transform, resulting in beam deflection with a focusing length of 20 µm. The simulated validation of the proposed compact optical switch demonstrated efficient beam deflection, yielding a 1 × 8 beam switching at a wavelength of 1550 nm. Combinations of diverse OPAs and metalens configurations resulted in potential scalability, allowing for the realization of optical switches with pathway numbers ranging from 4 to 16. This development of a metalens-assisted optical switch on a compact chip presents significant practical implications for enhancing data transmission efficiency and scalability in photonic integrated circuits. [ABSTRACT FROM AUTHOR]