The present invention is directed to an all-fiber-optic scanning endomicroscope capable of high-resolution second harmonic generation (SHG) imaging of biological tissues. The endomicroscope has an overall 2.0 mm diameter and consists of a single customized double-clad fiber, a compact rapid two-dimensional beam scanner, and a miniature compound objective lens for excitation beam delivery, scanning, focusing, and efficient SHG signal collection. Endomicroscopic SHG images of murine cervical tissue sections at different stages of normal pregnancy reveal progressive, quantifiable changes in cervical collagen morphology with resolution similar to that of bench-top SHG microscopy. A device according to an embodiment of the present invention can also be used to assess other pathologies, such as cancer. fibrosis, and inflammation. The present invention allows for diagnosis, monitoring of the effect of therapeutics, and surgical or interventional guidance. The present invention enables visualization of histology in-vivo, in the patient, and is label-free.
