Nonlinear Optical Transmission of Nanographene and Its Composites

Low-cost broad-band optical limiters based on nanographene have been studied, finding optical-limiting properties superior to those of current standards, carbon fullerenes (C 60 ) solutions and carbon black suspensions. Further examination indicates that the presence of π conjugation improves the optical-limiting responses. Superior limiting performance is retained regardless of solvent viscosity and polarity, a unique feature of graphene not observed in C 60 and carbon black. Graphene suspensions in organic solvents can work under 10 Hz laser pulses without losing excellent limiting performance. More significantly, outstanding limiting properties are also preserved in a gel matrix. These nanographene-based optical limiters can thus work in solutions and solid matrixes for devices used for protecting human eyes and optical sensors from high-power lasers.