Introduction to Spectroscopy - Vibrational Spectroscopy for Tissue Analysis - page 2

ABC D E F G H I

Figure 1.1 (See colour insert.)
Solar spectrum drawn and coloured by Fraunhofer with the dark lines named after him, 1817.
(Courtesy Deutsches Museum, Munich, Germany. With permission.)(1-3).

Figure 1.2
First grating spectroscope; Fraunhofer, 1821. (Courtesy Deutsches Museum, Munich, Germany.
With permission.)(1-3).

atoms and molecules possess minimum energy state E 0 , while after radiation
interaction they possess a higher energy state E* (excited state).

ΔE = E* − E 0

where
ΔE = energy difference
E* = excited state
E 0 = initial state