All-optical ultrasound imaging, where ultrasound is generated and detected using
light, has recently been demonstrated as a viable modality that is inherently insensitive to
electromagnetic interference and exhibits wide bandwidths. High-quality 2D and 3D all-optical
ultrasound images of tissues have previously been presented; however, to date, long acquisition
times (ranging from minutes to hours) have hindered clinical application. Here, we present the
first all-optical ultrasound imaging system capable of video-rate, real-time two-dimensional
imaging of biological tissue. This was achieved using a spatially extended nano-composite optical
ultrasound generator, a highly sensitive fibre-optic acoustic receiver, and eccentric illumination
resulting in an acoustic source exhibiting optimal directivity. This source was scanned across a
one-dimensional source aperture using a fast galvo mirror, thus enabling the dynamic synthesis
of source arrays comprising spatially overlapping sources at non-uniform source separation
distances. The resulting system achieved a sustained frame rate of 15 Hz, a dynamic range of
30 dB, a penetration depth of at least 6 mm, a resolution of 75 µm (axial) by 100 µm (lateral),
and enabled the dynamics of a pulsating ex vivo carotid artery to be captured