Measuring the 5D Excited Energy Levels of Rubidium Atoms Using Laser Spectroscopy

The valence electron of a rubidium atom can be excited from the 5D level to the Rydberg levels, including the nP levels and the “n” Stark manifold (e.g. n=50), via a third photon. In the Rydberg levels, atoms are very sensitive to external electric fields, and the energy-level shift observed can be used to measure the applied electric field that caused it. This phenomenon can be applied to an ongoing project on non-invasive electron beam imaging using rubidium atoms, as the electric field of the electrons will impact the energy levels of the atoms in the Rydberg levels. This project consists of the excitation, detection, and measurement of the 5D energy levels of rubidium using laser spectroscopy with two lasers at 780 nm and 776 nm, which one must first excite through in order to reach the Rydberg levels. The excitation process involves shooting a 780 nm laser through a cloud of rubidium atoms to excite them to the 5P3/2 level, then using a 776 nm laser to excite the atoms to the 5D5/2 states. The 5D energy levels are then detected and measured via the resulting emission spectrum, including detecting their decay to the 5S1/2 ground state at 420 nm through the 6P states. This process is completed in a vapor cell and a cold atom apparatus.