Research Interests
Light plays an essential role in our daily lives in situations ranging from seeing and distinguishing objects to developing technologies such as energy, telecommunications, and medicine. Manipulation of light and enhancement of light-matter interaction is thus important not only for fundamental studies on physics and material science but also for improving and miniaturizing optical devices as well as for enabling envisioned new devices.
Our team at UOU focuses on developing new innovative optical devices that can surpass existing devices. To realize this research vision, our research project is aimed at studying the electrical & optical properties of 2D materials including graphene and transition metal dichalcogenides (TMDCs) and by combining artificial 2D materials, so-called metasurfaces, and developing novel 2D material based metamaterials that manifest the potential to dynamically control optical properties in order to accelerate their practical applications.
Graphene-based metasurfaces
Seojoo Lee, Soojeong Baek et al. Advanced Materials, 32, 2000250
Among various controllable materials, graphene, a 2D lattice of carbon atoms, has similarities with metasurfaces in terms of its dimensionality. This makes it beneficial to utilize graphene for constructing active metasurfaces. Unlike conventional metals, the optical conductivity of graphene can be controlled easily by electric gating, chemical doping, or photoexcitation. We focus on developing graphene-based active metasurfaces with various designs of meta-atoms for controlling optical properties.
THz near-field spectroscopy
The resolution of a THz spectroscopic system can be limited by diffraction-limit. THz near-field time-domain spectroscopy system can overcome it is possible to measure the micrometer-scale resolution of an optical conductivity and mobility of 2D materials. Based on this tool, we are developing 2D materials based metadevices by maximizing the efficiency of electric and optical properties. Moreover, we focus on studying materials that could not be measured with conventional THz spectroscopy due to the limitation of sample size such as topological insulators, Weyl semimetals, etc.