Abstract
The primary experimental method used in atoms andmolecular physics is called spectroscopy, and it includes observing the light that passes through or exits when an atom or molecule changes its energy level in order to ascertain what state it is in.The variation in energy between the two states of being, which determines the frequency that light is absorbed or emitted, can be used to detect interactions that disturb those energy states.Spectroscopy is divided into a number of categories based on the electromagnetic radiation’s range and underlying principles. this review, we discussed, among other things, the Near Infrared Spectroscopy principle, equipment, and applications.
Keywords: Near infrared spectroscopy, Quality control, Pharmaceutical analysis, Quantitative analysis