Coupling manipulation enabled high-performance devices

Coupling is a fundamental phenomenon in optics, serving as the basis for the functionality of numerous optical devices. In this paper, we present our strategies for manipulating coupling to enhance both integration density and device performance. We experimentally demonstrate half-wavelength pitch waveguide arrays with low crosstalk in both the near-infrared and mid-infrared wavelength regions, as well as dual-polarization operation. Furthermore, we introduce a dispersionless coupling scheme to achieve broadband intensity distribution. These approaches enable significant reductions in on-chip footprint, which is critical for high-density photonic integrated circuits, and offer an efficient method for substantial device performance enhancement. Applications include on-chip optical phased arrays (OPAs) with wide field-of-view (FoV) and strong sidelobe suppression, as well as ultra-dense space-polarization-division multiplexing for high-capacity on-chip data transmission.