Physics Commons^™

Light is at once the most sensitive and the most gentle probe of matter.  It is commonplace for light to measure a picometer displacement far below the nanometer scale of atoms, or to capture the emission of a single photon from a fluorescent dye molecule.  Light is easy to generate using light-emitting diodes or lasers, and to detect using ultrasensitive photodetectors as well as the now ubiquitous digital cameras.  Light also has the uncanny ability to penetrate living tissue harmlessly and deeply, while capturing valuable information on the health and function of cells.  For these reasons, light has become an …