Swept Source Optical Coherence Tomography Endomicroscope Based on Vertically Integrated Mirau Micro Interferometer: Concept and Technology

This paper presents a concept of an endomicroscope for an early detection of neoplastic lesions in the human stomach tissue, based on the swept source optical coherence tomography (SS-OCT) and a measurement probe with integrated Mirau micro interferometer. The system consists of pigtailed illumination and detection blocks, connected via a Gradient Index (GRIN) lens collimator to a micro-opto-electro-mechanical systems (MOEMS) measurement probe (4 mm × 4 mm × 20 mm). The technology of Mirau micro interferometer is based on vertical multi-wafer bonding approach. The MOEMS probe is intended to be mounted on a continuum robot arm to perform in vivo microscopy of stomach tissues. First, the optical design of the SS-OCT endomicroscope is described, including an analysis of sensitivity. Then, we focus on the fabrication technologies and optical characterization of a key component of the Mirau micro interferometer, i.e., monolithically integrated focusing glass lens. SS-OCT endomicroscope will provide a fast axial scanning of tissues with A-scan sweep rate of 110 kHz, offering the axial resolution of 5.2 μm and the lateral resolution of 10.2 μm.