Two-dimensional materials for ultrafast lasers**Project supported by the National Natural Science Foundation of China (Grant Nos. 61378025 and 61427812), the Shuangchuang Team Program of Jiangsu Province, China, the National Key Basic Research Program of China (Grant No. 2014CB921101), and the State Key Laboratory of Advanced Optical Communication Systems Networks, China.

Abstract

As the fundamental optical properties and novel photophysics of graphene and related two-dimensional (2D) crystals are being extensively investigated and revealed, a range of potential applications in optical and optoelectronic devices have been proposed and demonstrated. Of the many possibilities, the use of 2D materials as broadband, cost-effective and versatile ultrafast optical switches (or saturable absorbers) for short-pulsed lasers constitutes a rapidly developing field with not only a good number of publications, but also a promising prospect for commercial exploitation. This review primarily focuses on the recent development of pulsed lasers based on several representative 2D materials. The comparative advantages of these materials are discussed, and challenges to practical exploitation, which represent good future directions of research, are laid out.