Scanning and Tunable Micro-Optics for Endoscopic Optical Coherence Tomography

Abstract

International audienceThe design, fabrication, and integration of microoptical components for beam focus and steering are demonstrated in an endoscopic optical coherence tomography (OCT) system. The relevant components, a membrane-based microfluidic tunable microlens and an electrostatic 2-D scanning micromirror, are fabricated using silicon and polymer-based microelectromechanical system technologies. All components are assembled inside a 4.5 mu m diameter probe. The design of the optical system, including substantiation of the need for focal length tunability, is presented, along with performance data of an OCT system using these components. A lateral resolution of about 13 mu is achieved, an improvement over fixed-focal length probes. Due to the miniaturization of the measurement head achievable using this optical microsystem, use in conventional endoscopes is possible