General features of molecular spectroscopy

This chapter covers the general features of molecular spectroscopy. It starts detailing the types of radiation found in emission spectroscopy, absorption spectroscopy, and Raman spectroscopy. Sources of radiation are either monochromatic which spans a very narrow range of frequencies around a central value or polychromatic which involves a wide range of frequencies. The underlying idea of a selection rule on transition lies in possessing, at least transiently, an electric dipole oscillating at a recommended frequency. The chapter looks into the Beer-Lambert law in formulating the transition with empirical results. It considers several examples of detectors and spectrometers in an effort to understand the conversion of radiation into an electric signal for processing and display.