Real-time acousto-optic imaging using high-peak-power long-pulsed illumination

Acousto-optic imaging (AOI) of absorbing objects embedded in highly scattering media remains challenging, since the detectable signal suitable for image reconstruction is weak. To increase the detected signals to a level required by live biological applications, we designed a high-peak-power quasi-continuous laser source based on the coherent combination of two pulsed amplifiers, delivering 100-µs-long pulses with a 9 W peak power at a 100 Hz repetition rate while maintaining an average power below 100 mW; jointly used with a digital holographic detection that maximizes the amount of collected signal, we demonstrate for the first time to our knowledge the optical imaging of 2-cm-thick highly scattering media (µ_s' ∼ 10 cm^-1) at near-video frame rate (0.2 Hz) using the Fourier transform-AOI.