ABSTRACT
This chapter provides a brief overview of light propagation in tissue and discusses the use of light for biomedical imaging, diagnosis and therapeutic applications. Biophotonics broadly deals with the interaction of photons, that is, light with biological matter. Such interaction plays an important role in our lives; photosynthesis and vision are good examples. For biomedical imaging applications, one would like to minimize absorption in tissue for two reasons; first, it would allow probing of larger depths of the tissue and, secondly, the deposition of energy in the tissue may result in irreversible changes. Therefore, one uses light in the so-called diagnostic window (700 nm to say 1300 nm) where tissue absorption is minimal. Biophotonic techniques also help to investigate biological systems with very high spatial and temporal resolutions in conditions close to physiological ones. Such studies contribute enormously to a better understanding of biological systems, which, in turn, should also help in better understanding diseases and their treatment modalities.
