This paper reports on our recent development of two-types of all-fiber-optic scanning endomicroscopy technologies for high-resolution optical imaging of internal organs. The first one is an OCT balloon catheter technology that permits systematic imaging of fine architectural morphologies of internal luminal organs over a large area. The second is a two-photon fluorescence endomicroscopy technology that enables assessment of tissue biochemical/ metabolic information with a superb spatial resolution. Both endomicroscopes have a small diameter (1.2-2.4 mm) and can be readily integrated with a standard clinical gastroscope, providing complementary information about tissue structure and function and helping improve diagnostic yield. We will discuss the basic design principles, major engineering challenges, solutions, and some preliminary results. In addition, we will also present our approach in developing near infrared (NIR) fluorescent nanocomplexes (ICG-micelles), which can be functionalized for active molecular targeting to improve molecular specificity and imaging contrast. These nanocomplexes, made of FDA approved building blocks, are biocompatible and very promising for clinical translation. Ultimately the NIR nanocomplexes can be used in conjunction with endomicroscopy technologies for performing high-resolution optical molecular imaging in vivo and in real time.