Yeyu Tong

Abstract Telecommunication systems are evolving towards ultrawide bandwidth and low latency, supporting wired and wireless links and their non-blocking interconnection1. However, a long-standing bandwidth mismatch between fibre communication and its wireless counterpart arises from fundamental disparities in signal architectures and hardware constraints2,3, which prevent high-speed and compatible transmission across the two domains.

Abstract Photonic bound states in the continuum (BICs) have been exploited in various systems and found numerous applications. Here, we investigate high-order BICs and apply BICs on an integrated photonic platform to high-dimensional optical communication. A four-channel TM mode (de)multiplexer using different orders of BICs on an etchless lithium niobate (LiNbO3) platform where waveguides are constructed by a low-refractive-index material on a high-refractive-index substrate is demonstrated.

Abstract We propose a novel high-efficiency, low-reflection, and fabrication-tolerant perfectly vertical grating coupler (PVGC) with a minimum feature size >200  nm to allow for fabrication using 193 nm deep-ultraviolet lithography. The structural parameters of PVGC were optimized by a genetic optimization algorithm. Simulations predicted the coupling efficiency to be −2.0  dB (63.0%) and the back reflections to be less than −20  dB in the wavelength range of 1532–1576 nm.