Miniaturized optical coherence tomography (OCT) endoscopes are crucial for minimally invasive imaging of internal organs. Current fabrication methods, however, struggle to correct optical aberrations, limiting resolution. This paper introduces a liquid shaping technique for rapid, scalable production of high-performance, ultrathin OCT microendoscopes. By controlling the energy state of curable optical liquid on a wettability-modified substrate, freeform microlenses with sub-nanometer surface roughness are created. 800-nm OCT microendoscopes (approx. 0.6 mm diameter) were fabricated and demonstrated ultrahigh-resolution imaging in rats' esophagi and mice's aortas and brains.

Chao Xu, Xin Guan, Syeda Aimen Abbasi, Neng Xia, To Ngai, Li Zhang, Ho-Pui Ho, Sze Hang Calvin Ng, Wu Yuan