We present a forward-looking OCT probe featuring a piezoelectric tube actuated resonant fiber scanner providing a fieldof-view of up to 1.8 mm with a lateral resolution of 12 μm. The fully packaged final probe has a total length of 11.3 mm and an outer diameter of 4 mm. The probe is designed to operate in contact mode, and can further be shortened by more than 30%, if configured to operate at a distance from tissue. The scanning fiber bears at its tip a plano-convex imaging lens of 1 mm diameter and 0.6 mm focal length. The two components are assembled via an ultra-high-precision holder, fabricated by a two-photon polymerization based 3D printing tool. This method provides an alignment accuracy better than 1 μm along all axes of the scanning fiber, leading to a good control of both the imaging parameters and the scan pattern around the resonance peak. Furthermore, using a plano-convex lens instead of a GRIN lens provides the same optical functionality within a significantly shorter length and facilitates further miniaturization. Using this probe, we demonstrate 3D OCT measurements of standard calibration targets and in-vivo tissue measurements performed on human skin.
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