Optical fiber curvature sensor used to measure the surface profile of 3D printing objects

A contact stylus profilometer based on an intensity-modulated optical fiber curvature sensor is proposed and demonstrated. The sensor head consists of a multimode-coreless-multimode (MCM) fiber structure, very sensitive curvature, clamped to a metal beam. The 3D printing stylus was glued to the center of the metal beam. The displacement of the stylus, during the surface scan of the 3D printing pieces, bends the metal beam, which in turn, induces a change in the curvature of the MCM producing a decrement of the losses of the characteristic attenuation notch. The profile generated with this simple-to-implement optical fiber sensor was compared with that obtained with a commercial stylus profilometer, observing a very good coincidence between both profiles.