Fluorescence enhancement with transient ultrasound light waveguiding

Ultrasound waveguiding of light is a recently introduced technique aiding light transport in scattering media, effectively reducing scattering strength. This technique locally, transiently, reversibly modifies the refractive index of the medium, recollecting and guiding some of the scattered photons to increase light intensity in depth. Here we use transient transversal ultrasound light waveguiding to increase the strength of the signal received from fluorescent target hidden behind a 3 mm thick scattering phantom. We use a common linear array transducer and transmission geometry and show waveguiding-induced increase of fluorescence, excited by a pulsed 532 nm light, typical for photoacoustic imaging setting.