The present invention is directed to a fiber optic device that enables multiphoton imaging with improved signal-to-noise ratio having a single piece of double-clad fiber (DCF). The device also includes all components for focusing, scanning and signal collection within an endomicroscope probe of 2.1 mm outer diameter (OD). The unprecedented imaging capability of this miniature endomicroscope is demonstrated herein via both ex vivo and in vivo experiments.
