Visible light nonlinear absorption and optical limiting of ultrathin ZrSe3 nanoflakes

摘要

The nonlinear absorption and nonlinear refractive properties of ZrSe3 nanoflakes were studied with a 6.5 ns pulse laser at 532 nm. Open-aperture Z-scan curves reveal that ZrSe3 nanoflakes have a strong reverse saturable absorption property, and close-aperture Z-scan curves show that ZrSe3 dispersions possess a positive nonlinear refractive index caused by self-focusing. The nonlinear absorption coefficient, the nonlinear refraction coefficient, and the figures of merit (FOM) of ZrSe3 dispersed in water with linear transmittances of 0.86 at input energy of 18 mu J are 6.35 x 10(-10) m W-1 15.73 x 10(-17) m(2)W(-1), and 10.09 x 10(-11) esu center dot cm respectively. In addition, nonlinear optical (NLO) performance of ZrSe3 nanoflakes depends on organic solvent dispersions. ZrSe3 nanoflakes in water dispersions have the largest FOM of 10.27 x 10(-11) esu center dot cm, while the FOM in ethanol dispersions is 5.41 x 10(-11) esu center dot cm at the same input energy of 26.5 mu J. The optical limiting threshold F-th of ZrSe3 nanosheet is 2.2 J cm(-2) under picosecond laser pulse. The Results imply that ZrSe3 nanoflakes are an extraordinarily promising material for novel nanophotonic devices like optical limiters.