Abstract

We report a step toward scanning endomicroscopy without distal optics. Indeed, we realized a video-rate lensless point scanning endoscope where the size of the endoscope distal probe was reduced to the fundamental limit— the 400 µm diameter of the endoscope fiber itself. Following in the footsteps of coherent laser beam combining, the focusing of the beam at the distal end of a fiber bundle is achieved by imposing a parabolic phase profile across the bundle exit face with the aid of a two-dimensional spatial light modulator (SLM). We used a bundle of single mode fiber (SMF) cores specifically designed for the purpose which exhibits extremely low cross-talk between the individual cores. This allows video-rate transverse scanning of the focal spot by using scan mirrors before the SLM.

© 2013 IEEE