Superradiant Anti-Stokes Fluorescence of Organic Dye J-Aggregates

Abstract

Molecular emission with shorter wavelengths than the excitation light has diverse applications in biology, chemistry, and physics. Anti-Stokes fluorescence (aSFL), which occurs when molecules in thermally excited vibrational states undergo electronic transitions and emit fluorescence, offers the advantage of being a one-photon process that does not require high-intensity, focused light, unlike multiphoton up-conversion. However, only a few organic dyes exhibit weak, spectrally broad aSFL, limiting their usage. Here, it is demonstrated that the superradiance of dye J-aggregates enables bright and spectrally narrow (width of ≈6 nm) aSFL emission. Furthermore, it is shown that this J-aggregate aSFL (J-aSFL) enables real-time, wide-field imaging, which is not possible with other multi-photon methods or with monomeric aSFL. It is found that J-aSFL is a general property across various dyes, allowing structurally tunable, narrow-band emission suitable for multiplexed imaging of bio-samples. Beyond imaging, the results also open new opportunities for local temperature sensing and optical cooling of organic solids.