A 3D-printed reflective lens fabricated via 2-photon polymerization for flexible catheter endoscopy

We present a flexible catheter endoscope using a 3D printed miniature side-viewing reflective lens for OCT imaging. A reflective lens with a depth of field (DOF) of 3mm and a maximum spot size of 80 microns was first designed and optimized in OpticStudio (ZEMAX). The structure of the lens and the fiber mating part of the optic was then constructed using 2-photon polymerization technique, and a gold reflective coating was added as the final step for the reflective lens. The reflective lens was then glued to cleaved optical fiber, and the assembly was covered by a torque coil to allow rotation of the catheter endoscope. This endoscope was used with a fiber-optic rotary joint and custom-built Mach-Zehnder interferometer to acquire OCT images.