Optical data storage with diffraction-unlimited resolution

Optical data storage is an important and critical part of optical information technology in which case photons rather than electrons are used for information generation, processing, transmission and storage. We have witnessed the revolution of photonics in optical communications. The advance in photonic chips will allow for the development of ultrafast optical signal generation and processing. While optical data storage such as the optical compact (CD) disk, digital video (DVD) disk and Blue-ray disk technologies has transformed our society in the last two decades, the development in this area has been slow down and seemingly become less active due to the fast development of flush memory and hard disks. However, the optical data storage technology has held its distinctive advantages of long lifetime, low-energy consumption, and ultra-secure encryption [1-3]. Nanophotonics that is the integration of photonics and nano-materials has extended optical data storage from three-dimensions to five dimensions or more [1, 2]. If combined with supresolution optics that allows for the break of the diffraction limit, nanophotonics-enabled optical data storage will make it possible to develop Petabype optical disks, forming a green-technology platform for future data centres.