Two‐Photon Absorption and the Design of Two‐Photon Dyes

Abstract Two photons are better than one : This principle applies to a wide range of applications, ranging from engineering to physiology. Recent advances in our understanding of the phenomenon of two‐photon absorption (see picture) and in the design of two‐photon dyes are rapidly increasing the scope of this field. magnified image Two‐photon absorption has important advantages over conventional one‐photon absorption, which has led to applications in microscopy, microfabrication, three‐dimensional data storage, optical power limiting, up‐converted lasing, photodynamic therapy, and for the localized release of bio‐active species. These applications have generated a demand for new dyes with high two‐photon…