Influence of optical probe packaging on a 3D MEMS scanning micro-mirror for optical coherence tomography (OCT) applications

An optical probe is developed for imaging in an optical coherence tomography (OCT) system. A 3D micro mirror is used for steering the beam from the source to the sample. A GRIN lens, fiber and micro mirror are assembled in a silicon optical bench. The assembled components are housed in the bio-compatible microinjection molded housing. The images obtained using this probe is studied with respect to probe assembly. Tolerance of GRIN lens placement, micro mirror placement on the substrate, deformation of the mirror, housing transparency and housing curvature are studied with respect to the final image from the probe. In this study it is found that a higher mirror curvature affects the depth of focus on the sample and mirror placement reduces the coupling efficiency during the optical assembly.