A 2.8-MM imaging probe based on a high-fill-factor MEMS mirror and wire-bonding-free packaging for endoscopic optical coherence tomography

This paper reports a miniature optical coherence tomography (OCT) probe and high-resolution 3D OCT imaging results obtained with this probe. The probe is only 2.8-mm in diameter, enabled by a unique high-fill-factor electrothermal MEMS mirror with hidden actuators and a novel wire-bonding-free (WBF) packaging technique. The MEMS mirror has a large mirror aperture of 1 mm with a chip size of only 1.55 × 1.7 × 0.5 mm
³
. The fabricated device achieves large 2-D scan optical angles up to 46° at only 4.8 V. High-resolution 3D OCT imaging results are also demonstrated using this assembled probe.