Bessel-beam intravascular optical coherence tomography (OCT) with a 3D-printed micro-axicon probe

We have developed a Bessel-beam probe that achieves ~8 μm lateral resolution over an ∼800 μm depth of focus using a 3D-printed side-facing micro-axicon lens. Fabricated via single-step two-photon polymerization 3D printing directly on the fiber facet, the micro-axicon (<260 μm diameter) corrects for astigmatism and other aberrations common in miniaturized beam-shaping systems. This 3D-printed Bessel-beam probe demonstrates superior image quality compared to standard gradient-index-fiber-based probes, validated through ex vivo imaging of human atherosclerotic plaques and longitudinal in vivo imaging in a diabetic swine model of coronary artery disease. The swine model, anatomically and physiologically similar to humans, represents a critical preclinical step toward clinical translation. To our knowledge, this is the first demonstration of in vivo coronary imaging using a 3D-printed micro-optic, marking a major advance toward the clinical adoption of beam-tailored, miniaturized imaging probes.