Ultra-thin flat lens for sub-diffraction limit focusing and imaging

Abstract

Flat optics with micro-nano-structures fabricated on a thin film has shown strong power in light manipulation and is promising for integrated optoelectronics for its compactness and compatibility for large volume manufacturing. In this talk, I will introduce flat lenses to break the diffraction limit and their applications in medical imaging and high density data storage. By engaging the strong excitonic absorption in 2D materials, ultra-thin flat lenses in MoS2 is demonstrated for sub-diffraction limit imaging. Furthermore, high electrical tunability in refractive index is achieved in monolayer WS2 in an optical cavity for potentially tunable ultra-thin flat lenses.