Experimental observation of enhanced reverse saturable absorption in Bi 2 Se 3 nanoplates doped PMMA thin film

Abstract

By employing the ultrafast Z-scan technique, we characterize the nonlinear absorption property of PMMA/Bismuth Selenide (Bi 2 Se 3) composite with varying concentrations. We report the fabrication of bismuth selenide (Bi 2 Se 3) nanoplate (topological insulator (TI)) doped poly methyl methacrylate (PMMA) thin film with varying doping concentrations. The effect of Bi 2 Se 3 on structural and linear properties of PMMA thin film has been investigated through UV-Vis spectroscopy, scanning electron microscope (SEM), and Energy dispersive x-ray spectroscopy (EDS) elemental mapping techniques. Furthermore, the nonlinear optical absorption property of PMMA and PMMA/Bi 2 Se 3 composites have been performed employing a single beam open aperture z-scan technique under femtosecond laser excitation at 750 nm. The z-scan results exhibit an enhancement of reverse saturable absorption (RSA) property with an increased nonlinear absorption coefficient (β) of the PMMA/Bi 2 Se 3 composites compared to pure PMMA measured with intensity at 320 GW cm−2. The RSA response gets enhanced with the increase in doping concentration also. Our experimental observations reveal that PMMA/Bi 2 Se 3 composite can provide a promising platform to realize photonic devices such as optical limiters, optical switches, and efficient protectors from high power sources.