ABSTRACT
Physics owes its understanding of atomic and molecular structure to spectroscopy. Spectroscopy also once enabled physicists to determine the numerical values of a number of fundamental constants. Today this is history. Modern spectroscopy is an important area of applied physics aimed at solving practical problems in a vast range of scientic and technological endeavor, from metallurgy to microbiology and ecology. To meet these modern challenges, we no longer use classical spectrographs. Instead, they have formed the basis for the development of numerous advanced special devices. We shall not go into all the countless detail concerning these devices but rather concentrate on the set of fundamental principles underlying spectroscopy, and how they are revealed in some key design features of spectral devices.
