SUMMARY It is essential that technological advances in imaging developed in the laboratory find direct translational paths to rapidly demonstrate their clinical utility in patients, and establish the potential for improving detection, diagnosis, and monitoring of disease. While label-based optical imaging modalities have demonstrated potential in intraoperative cancer detection, mapping the microvasculature, and site-specifically targeting of altered metabolism and pathology, to name a few, these approaches often come at a significant time and financial cost due to the associated safety risks and lengthy review processes required for FDA approval of any new contrast agent or probe. Importantly, any new targeted contrast agent or probe inevitably will have some degree of non- specific binding or off-target labeling, as well as a variable degree of uptake or labeling of the targeted cell or site. In the end, the measured or imaged signal levels are always questioned. Is the signal low because the targeted pathology is minimal, or because the targeted efficiency of labeling is low? The importance of label-free imaging is therefore high, and the need for label-free imaging across size scales is great. By identifying robust label-free signals or biomarkers that indicate changes in structure, molecular composition, metabolism, and function, quantitative clinical and in vivo imaging not only becomes a feasible alternative to label-based methods, but also provides a direct and rapid translational path to clinical human studies, since regulatory approval is not additionally needed for a contrast agent or probe. This enables rapid in vivo first-to-human and limited-scale human subjects research studies (and subsequently larger clinical trials) to be performed with the new optical imaging technologies, and make early determination of the clinical utility of the technologies and the new optical biomarkers that they generate. This TRD focuses on the technological development through four specific aims that progress from 1) the sub-cellular and cellular scale, identifying optical biomarkers and signatures that would indicate more systemic disease processes, to 2) tissue sections in an advanced digital pathology platform with artificial intelligence, to 3) computational optical imaging algorithms that extend the depth and performance of optical imaging in thick tissues, and finally to 4) engineered beam delivery systems to widely expand tissue access and application for these label-free optical imaging modalities. Collectively, this project will demonstrate novel technological advances that will find a myriad of applications to advance the biological and medicine sciences, and improve diagnostic and monitoring capabilities in clinical medicine.