Structure and characterization of an enhanced laser-scanning endoscope based on microelectromechanical mirrors

A miniaturized laser-scanning endoscope is presented that makes use of a composite laser beam for color imaging. A novel approach is followed in the device, which is based on scanning the target tissue with the laser beam using two miniaturized MEMS (microelectromechanical systems) micromirrors and employs specific collection, detection, and postprocessing of the scattered light for reconstructing a color image of the tissue. A resolution of the order of 16 line pairs/mm is achieved for a working distance of 50 mm while the focal depth is larger than 5 mm. Key considerations of the system design are presented, along with results on the operation of the micromirrors, an analysis of the optical design of the endoscope head, and remarks on the assessment of image quality. © 2006 SPIE and IS&T. DOI: 10.1117/1.2194890