Characterization of organic nonlinear optical materials for optical limiting applications

We have examined several classes of organic materials, including diphenyl polyenes, dithienyl polyenes, thiophenes, benzithiazoles, carbocyanines, porphyrins, phthalocyanines, and fullerenes, for applications as optical limiters. Materials characterization is accomplished primarily by nonlinear transmission (e.g., Z-scan) and pump-probe experiments. Interesting phenomena arise in these experiments which require careful analysis to extract meaningful nonlinear absorption coefficients. In this paper, we present measurements of several organic materials and elucidate the fundamental nonlinear optical properties, all at 532 nm.