All-Fiber Coaxial Focus Multimode Beam Probe for Optical Coherence Tomography

Breaking through the limitation of depth-of-focus (DOF) and lateral resolution in fiber focusing optics for optical coherence tomography (OCT) has been challenging. In this paper, we propose an all-fiber coaxial focus multimode beam probe for high resolution OCT imaging applications. A DOF of
$\mathbf{820}\ \boldsymbol{\mu} \mathbf{m}$
and a lateral resolution of
$\mathbf{4.9}\ \boldsymbol{\mu}\mathbf{m}$
were achieved experimentally. It is demonstrated that the proposed OCT probe can precisely profile the layer-by-layer structure of a multi-layer translucent tape, revealing more refined details.