Recently, the 40-page review paper entitled “Graphene and its derivatives for laser protection”, which is coauthored by researchers in Prof. Jun Wang’s group from Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, and Prof. Yu Chen’s group from East China University of Science and Technology, has been published on Progress in Materials Science. Progress in Materials Science, one of the top international journals on materials science, publishes authoritative and critical reviews of recent advances in the science of materials and their exploitation in engineering and other applications. The impact factor is 31.083, and 5-year impact factor is 33.505.

Figure 1. A literature statistics using the ISI Web of Science restricted to the most plausible candidates for OL shows a significant increasing trend in publications.

Since the coming out of the first operation laser in 1960, new and improved laser technology for civilian purposes has continued to be at the forefront of research activities over the world. Because lasers are coherent, monochromatic and travel in only one direction, they are uniquely adapted for numerous important applications such as presentation pointers, medical cosmetology, scanning and ranging devices, and surgery operation as well. However, along with its development, lasers are becoming increasing threats to human eyes, optical sensors, and some other traditional optical windows, etc. Therefore, the need for passive laser protectors to protect human eyes and all optical sensors from intense laser beams is growing societal problems that can only escalate.
The development of functional materials for laser protection is an extremely important research field for the safety and security of users. To achieve simultaneous protection against both pulsed and continuous wave (cw) or quasi-cw lasers, significant research effort has been invested into state-of-the-art broadband optical limiting (OL) materials and processes in an attempt to achieve some measure of protection from such laser beams in the past decades. As the first truly two-dimensional material, graphene is being considered as an ideal material for modern photonic, optoelectronic and electronic devices because of its fantastic physical properties. Graphene shows ultrafast carrier relaxation dynamics and ultra-broadband resonate nonlinear optical (NLO) response due to their extended ？-conjugate system and the linear dispersion relation holding for their electronic band structure. Almost all types of graphene-based materials described in this review exhibit strong broadband OL response. The dominant limiting mechanism of graphene is nonlinear scattering, which is very effective in liquid suspensions rather than in solid state hosts. In contrast to the pure graphene, the solubilized graphene and its derivatives optically limits through nonlinear absorption mechanism, nonlinear scattering as well as the photoinduced electron transfer and/or energy transfer between graphene and organic/polymeric species. This review described systematically the OL mechanisms and the recent achievements on the graphene-based functional materials (i.e., graphene nanostructures, graphene composites, and covalently modified graphene) for OL applications. The future major ongoing areas of effort have also been suggested, including (1) design and synthesis of new graphene-based functional materials for laser protection; (2) determination of the relationship between the structural parameters and the OL response while seeking to optimally combine materials and devices; (3) development and demonstration of a laser protection prototype system; and (4) development of new laser protection concept designed to meet the practical requirements and innovative technology approaches to protect human eyes and optical sensors from frequency-agile lasers.

This paper was published on Progress in Materials Sciences on 19 Sept. 2016.
[http://www.sciencedirect.com/science/article/pii/S0079642516300603]
This work was supported by the Chinese National Natural Science Foundation, the Strategic Priority Research Program of CAS, and the Key Research Program of Frontier Science of CAS.