Nonlinear optical absorption in PVA films doped by the novel natural dye extract from C. redflash leaves

Abstract

In this work, we investigate the linear and nonlinear optical properties of polyvinyl alcohol (PVA) films doped by the natural dye extract from Caladium redflash (C. redflash) leaves. Linear optical properties of the doped films are tuned by varying the dopant concentration. Nonlinear absorption of the films is measured using 5 ns laser pulses at the wavelength of 532 nm, employing the open aperture Z-scan technique. The films show excellent optical limiting efficiency which arises from strong reverse saturable absorption at this wavelength, making them potential candidates for device applications in eye and sensor protection. These green, durable and cost-effective films can also be used as economical substitutes for costly transparent optical coatings made using synthetic dyes.