Strong Two‐Photon Excited Fluorescence and Stimulated Emission from an Organic Single Crystal of an Oligo(Phenylene Vinylene)

Low in, high out: Single crystals of a thiomethyl-terminated oligo(phenylene vinylene) exhibit unique photonic properties including strong anisotropic solid-state fluorescence (see depicted optical and fluorescence micrographs; arrows: polarization direction), high quantum yield, large two-photon absorption cross section, and stimulated emission, which make it a candidate for opto-electronic applications such as upconversion lasing.