Designing of PVA/Rose Bengal long-pass optical window applications

Abstract

Poly(vinyl alcohol) (PVA)/Rose Bengal (RB) composite films were prepared by casting technique form aqueous solutions doped with different dye concentrations. The effect of dye concentration on the structure, spectroscopic and optical properties was characterized by X-ray diffraction, optical absorption and fluorescence spectroscopy. The optical limiting properties of PVA/RB films were measured using He-Ne laser beam at 632.8 nm wavelength and showed the best optical limiting behavior at high dye concentrations. The results were interpreted on the basis of hydrogen bonding between hydroxyl groups in PVA and the carbonyl group of face-to face stacked H-aggregates of RB molecules which was evident by all the characterization techniques. Furthermore, PVA/10 wt% RB film showed excellent optical cut-off properties in the spectral range (600–1400 nm) with a high transmission value (Σ 84%) which is a promising result for the long-pass optical filters and protective window applications. Keywords: PVA, Rose Bengal, H-aggregates, Optical limiting, Long-pass filter