River Beard is a physics student at Bethel University. River is driven to learn how the universe works and wants to use science and engineering to improve the lives of individuals and societies. River is researching the 5S – 5D two-photon transition in Rubidium as an optical frequency standard. The frequency standard can be deployed in the field for applications such as atomic clocks on GPS satellites because the two-photon absorption eliminates the first-order Doppler shift and the need for laboratory-bound laser cooling apparatuses. The 778nm wavelength of the interrogating light allows for greater precision than commonly used microwave transitions. At Bethel University, they are studying geometric solutions, along with varied polarization-states of interrogating light, to reduce the AC-Stark shift in the interest of long-term clock stability, while keeping quantum shot-noise at a minimum in the interest of short-term clock stability.
