Our research interests now include on-chip metamaterials, lithium-niobate electro-optic devices, inverse design of photonic devices and systems.
Metamaterial is an emerging composite whose electromagnetic properties can be engineered by structuring its constituents. On-chip design of metamaterials permits it to be integrated with other optical elements, including waveguides, resonators and interferometers. On-chip metamaterials enable exploring metamaterials’ novel physics and broad applications in integrated optics.
Lithium-niobate electro-optic devices
Lithium niobate (LiNbO3) on insulator (LNOI) is a promising material platform for integrated photonics due to single crystal LiNbO3 film’s wide transparent window, high refractive index, and high second-order nonlinearity. Based on LNOI, the fast-developing ridge waveguide fabrication techniques enabled various structures, devices, systems, and applications.
Inverse design of photonic devices and systems
Device design has long been the first and the most important step in making nanophotonics. Successful nanophotonics device design allows us to effectively manipulate the electromagnetic fields inside the design region at wavelength scale or even sub-wavelength scale.In the context of performance-driven device design, inverse design method came into being. Inverse design seeks the best topology structure satisfying the objective function defined by the required performance, by using a series of inverse design methods such as evolutionary method, topology optimization based on adjoint variable method, direct binary search, machine learning, etc, through which a large number of degrees of freedom can be simultaneously computed. Inverse design’s common feature is a known optimization objective function, which inversely derives the characteristic parameters of the system under the guidance of certain system evolution rules such as motion equations and differential operators. This method is widely applied in the design of photonic materials, devices, and systems for the applications in various areas, including electromagnetics, plasmonics, photonic crystals, and integrated photonics.