Optical Pumping of Natural Rubidium

In 1950, French physicist Alfred Kastler introduced the concept of modern optical pumping, for which he was awarded the Nobel Prize in 1966. The process of optical pumping involves using photons of a desired wavelength and polarization to change the distribution of a gas of atoms from thermal equilibrium. Today, optical pumping is a critical tool in modern Physics experiments, and is the basis of lasers. This process utilizes quantum mechanical ideas, and can therefore be used to gain a better understanding of quantum and atomic theory. In this experiment optical pumping processes were performed on natural Rubidium gas, which is a mixture of Rb-87 and Rb-85. Because Rubidium only has a single valence electron, it can be approximated as a singleelectron atom (i.e. Hydrogen). Optically pumping the Rubidium sample achieved two main goals, which was the determination of the nuclear spin angular momenta (I) for each isotope, as well as the confirmation of Zeeman splitting due to a magnetic field according to the Breit-Rabi equation. In Section (II), the theory behind the optical pumping is discussed. Section (III) explores the experimental setup and procedure. The results and their analyzations are in Section (IV), and the conclusions can be found in Section (V).