Faraday polarization rotation control of 1529nm wavelength between excited states of Rb atoms

Faraday polarization rotation control of 1529 nm wavelength has been obtained using the 5S(1/2) -> 5P(3/2) -> 4D(5/2) transition of rubidium. The traditional off-resonant polarization rotation method commonly used in the Faraday effect for direct transitions of atoms is not applicable to the transitions between excited states. In this study, we proposed a near-resonant polarization rotation method using the Faraday effect between excited states of atoms, by which the polarization rotation of the rubidium 5P(3/2) -> 4D(5/2) transition can be controlled from 0 degrees to 90 degrees with low distortion. The 780 nm pump light corresponding to the 5S(1/2) -> 5P(3/2) transition can also be used simultaneously as a control source to manipulate the polarization state of the 1529 nm optical signal.