Indole Based Molecular Systems For Third Order Nonlinear Optical Applications

This article reports the Z-scan-derived nonlinear optical and optical limiting characteristics of a series of indole-based (2,3-benzopyrrole) polymeric systems. While the monomeric form exhibits negligible nonlinear optical response under nanosecond excitation regime (Nd-YAG, 7ns, 532nm), its polymeric derivatives–Polyindole (IND-2), Allyl polyindole (IND-3), and Benzyl polyindole (IND-4)–show markedly enhanced nonlinear optical behavior, accompanied by low optical limiting thresholds of the order of 0.027GW/cm 2 . Lorentzian-Gaussian deconvolution of photoluminescence spectra was performed to elucidate the linear optical emission characteristics of each molecular system. The underlying mechanisms governing nonlinear absorption and optical limiting in each system are examined in detail. Solid-state feasibility was assessed using thin films of the materials doped in a PMMA matrix.