Structural, morphological, nonlinear optical and power limiting properties of acid green 3 dye-doped PVA films

Acid green 3 (AG 3) dye-doped poly(vinyl alcohol) (PVA) films were formed on microglass slides via solution casting technique; their structural, morphological, linear, nonlinear optical and power limiting characteristics were studied. AG 3-PVA films were characterized by UV–visible spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, atomic force microscopy and scanning electron microscopy methods. The nonlinear optical absorption and refraction properties of AG 3-PVA films were studied by Z-scan technique using a 5 mW diode laser of 635 nm wavelength. AG 3-PVA films were found to exhibit a consistent reverse saturable absorption phenomenon and negative optical nonlinearities; their χ(3) values were measured to be of the order of 10^-5 esu and optical power limiting behavior was also observed for these films. Based on the results of the present experimental work, we suggest that AG 3-PVA films may be suitable for optical limiting, photonic and optoelectronic applications in the low-power regime. (author)