Integrated nanophotonics with subwavelength grating metamaterials

Abstract

Photonic integrated circuit (PIC) technology is rapidly advancing, offering cost-effective, scalable, and portable solutions by miniaturizing complicated optical systems. However, akin to the evolution of semiconductor chips, the challenges of integration density are emerging, directly affecting scalability and cost. In this tutorial, I will review recent breakthroughs and advances in increasing the integration density of PIC, especially via subwavelength grating metamaterials. Two key fundamental concepts – skin-depth engineering and anisotropic perturbations – will be discussed that can uniquely manipulate modal confinement and couplings via the anisotropic characteristics of subwavelength gratings. I will then examine how these unique properties of subwavelength gratings have been utilized to enhance component-level photonic devices. Finally, I will address challenges related to the practical use of anisotropic metamaterials and discuss the perspectives on the future.