Organic dye impregnated poly(vinyl alcohol) nanocomposite as an efficient optical limiter: structure, morphology and photophysical properties

A new polymer based nanocomposite system comprising the organic chromophore Light Green (LG) has been fabricated using poly(vinyl alcohol) (PVA) as the host template, and its structure, morphology, and linear and nonlinear optical properties have been investigated. Microstructural analysis reveals a semicrystalline nature of the nanocomposites, with a uniform dispersion of nanoclusters of dye molecules encapsulated between the molecular chains of the host polymer PVA. XRD, FTIR and electrical conductivity studies indicate considerable interactions between the dye molecules and the polymer chains. LG-PVA nanocomposite films exhibit PL emission in the red region of the visible spectrum, when excited in the vicinity of their absorption maximum (645 nm). The composite films also display nonlinear absorption and optical limiting behavior under nanosecond (5 ns) Nd:YAG laser light excitation at 532 nm. The LG-PVA nanocomposite films are found to possess a high laser damage threshold, improved thermal and photostability, and excellent durability, which signify the scope of utilizing them as smart materials for applications in optoelectronic nanodevices.