Fabry-Perot (FP) ultrasound sensors are widely used for Photoacoustic Tomography (PAT), affording high resolution (<100 μm) images, with a penetration depth of about 1 cm, limited by system's sensitivity. The sensitivity is, in turn, limited by the shape of the Gaussian beam typically used to interrogate the FP sensor, which is not well "confined" inside the FP cavity. To overcome this limitation, a novel PAT system employing Bessel beam to interrogate the FP sensor was prototyped. Unlike Gaussian beams, Bessel beams are well confined in the FP cavity, increasing the system's sensitivity by multiple orders of magnitude, paving the way to multi-centimetre clinical PAT imaging with high resolution
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