ABSTRACT

Over the past two decades, optic and photonic technologies have become exceedingly ubiquitous in the key enabling devices that are central to many aspects of everyday life. In multicellular organisms, the basic building blocks of life are the cells. These membrane-encapsulated units are composed of an abundant number of molecules and molecular complexes, which provide functionality to the cell. Scattering describes the change in the direction of propagation and, sometimes, energy of light when incident on heterogeneities within a bulk medium. The heterogeneities are usually nonuniform spatial and/or temporal distributions of the refractive index in the medium due to physical inclusions or random thermal motion. Absorption is the transfer of energy from light to a molecular species. It occurs when the photon frequency matches the "frequency" associated with the molecule's energy transitions. In addition to nonradiative relaxation pathways, energy absorbed by some molecules can be dissipated by emission of radiation.