Adaptive All-Optical Ultrasound Imaging Through Temporal Modulation of Excitation Light

Abstract

In this work, we demonstrate how the wide acoustic bandwidths generated by all-optical ultrasound imaging probes can be leveraged to dynamically trade-off image resolution with penetration depth. This dynamic trade-off was achieved through temporal modulation of the excitation light using bandwidthlimited linear chirps. The penetration depth of the all-optical ultrasound imaging probe used here could be arbitrarily set between 2 and 15 mm, to achieve inversely proportional spatial resolutions ranging from 128−500 µm (lateral) and 189−295 µm (axial). This added versatility in image parameters will enable seamless multi-scale ultrasound imaging that can strongly benefit interventional imaging.

Comparison of Fabrication Methods for Fiber‐Optic Ultrasound Transmitters Using Candle‐Soot Nanoparticles

“…The low cut-off of 10 MHz was chosen to remove the low ultrasound frequencies which contribute to signal broadening and beam divergence, reducing the achievable lateral resolution. [20,54] Cross-talk originating from direct transmission of ultrasound from the CSNP-PDMS composite surface to the ultrasound receiver was then removed through a general linear model [9] and then processed by digital time gain compensation to reduce the impact of wave attenuation. Subsequently, synthetic aperture imaging was performed by concatenating processed signals from different locations which then underwent k-space reconstruction using the k-Wave toolbox.…”

Tailored Photoacoustic Apertures with Superimposed Optical Holograms

“…Photoacoustic phase modulation can be carried out by temporal modulation of the incident laser pulses. Previous implementations have used free-space [17,10] or fiber-based delivery [18,19,20,21,22,23,24,25,26,27,28], however these methods typically produce static linear phased arrays which are fixed in both number and size. Acoustic phase variation can also be achieved by the use of acoustic lenses which, analogous to optical lenses, directly modulate the incident acoustic pulse [29,30,31,32,33,34,35,36].…”