Atomically thin optical lenses and gratings

Title	Atomically thin optical lenses and gratings
Authors	Jiong Yang, Zhu Wang, Fan Wang, Renjing Xu, Jin Tao, Shuang Zhang, Qinghua Qin, Barry Luther-Davies, Chennupati Jagadish, Zongfu Yu, Yuerui Lu
Magazine	Light, Science & Applications
Date	03/11/2016
DOI	10.1038/lsa.2016.46
Introduction	Two-dimensional (2D) materials are receiving attention for miniaturised optoelectronic applications due to their strong inelastic interactions with light. Effective miniaturised optical systems also require substantial elastic light–matter interactions for precise light flow control. This study presents findings on single-layer molybdenum disulphide (MoS2), which exhibits an exceptional optical path length (OPL) – approximately ten times greater than that of single-layer graphene. Leveraging this considerable OPL to tailor the phase front of optical beams, we have developed the thinnest optical lens known, comprising just a few layers of MoS2, under 6.3 nm thick. Furthermore, by utilising the significant elastic scattering efficiency inherent in ultra-thin, high-index 2D materials, we have also created high-efficiency gratings using single- or few-layer MoS2. The ability to precisely manage light propagation within 2D materials allows for miniaturisation of optical components and the integration of advanced optical features. Importantly, the distinct and broad tunability of MoS2's refractive index via electric fields enables diverse applications in electrically adjustable atomically thin optical elements, including micro-lenses with variable focal lengths and accurate electrical phase shifters, functionalities not achievable with conventional bulk materials.
Quote	Jiong Yang, Zhu Wang and Fan Wang et al. Atomically thin optical lenses and gratings. 2016. DOI: 10.1038/lsa.2016.46
Element	Molybdenum (Mo) , Sulfur (S) , Carbon (C)
Materials	Chemical Compounds
Topics	Photonic and Optoelectronic Materials , Smart and Functional Materials
Industry	Electronics , Optics , Research & Laboratory