duafoton

Duafoton is a class of synthetic organic chromophores developed for nonlinear optical applications, notably in two-photon processes. The term is derived from the concept of dual or two-photon interactions and is used to describe molecules engineered to exhibit strong two-photon absorption and tunable emission properties.

Duafotons typically feature a donor–acceptor–donor architecture with extended pi-conjugation, allowing broad absorption bands and high two-photon absorption cross-sections. These molecules are designed for good photostability and color tunability, enabling emission across a range from visible to near-infrared regions by substituent choice. Their optical properties can be further modulated by solvent environment and molecular conformation.

In practical use, reported two-photon cross-sections for duafotons span a wide range, often measured in hundreds to thousands of Goeppert-Mayer units (GM). Emission lifetimes are compatible with common fluorescence detection systems, facilitating integration into imaging and photonic setups. Duafotons are therefore considered versatile for applications that require efficient two-photon excitation and bright fluorescence.

Applications for duafotons include two-photon fluorescence microscopy and deep-tissue imaging, where their excitation in the near-infrared region enables improved penetration and reduced scattering. They are also explored for multiphoton photolithography and optical data storage, as well as for nonlinear optical devices such as frequency conversion materials. Synthesis of duafotons generally involves constructing the donor–acceptor framework through cross-coupling or condensation reactions, followed by functionalization to tailor solubility and photostability.

See also: Two-photon absorption, Nonlinear optics, Organic dyes.