Perspective on remote photonic bio-sensing and diagnosis

In this Perspective Letter, we discuss the field of remote photonic bio-sensing and diagnosis while focusing on sensing involving spatial analysis of temporally varied defocused secondary speckle patterns. Collecting secondary speckle patterns that were back-reflected from an inspected tissue while properly defocusing the imaging lens allows us to measure nano-vibrations occurring in the tissue. The nano-vibration signal can serve as the common denominator for simultaneous estimation of many bio-medical parameters related to vital bio-signs, hematology, and hemodynamics. This can provide a powerful tool for comprehensive medical diagnosis.