Study on an all-fiber optical coherence tomography (OCT) probe

•An all-optical fibre optical coherence tomography(OCT) probe is designed,which has the advantages of small size and high-resolution.•The optical transmission model of the probe is developed, and then the structural design of the probe is modelled.•The addition of a GRIN fibre to the middle of the NCF reduces the beam waist size without lowering the focal length.•An SD-OCT system was built for the imaging experiments. The feasibility of the probe was verified by obtaining grey-scale images of the triple-layer slides.