Active stabilization of alkali-atom vapor density with a solid-state electrochemical alkali-atom source
Songbai Kang, Russell P. Mott, Allison V. Mis, Christopher S. Roper, Elizabeth A. Donley, John E. Kitching
We report a demonstration of vapor-phase Rubidium (Rb) density stabilization in a vapor cell using a solid-state electrochemical Rb source device. Unlike the traditional passive methods, e.g. stabilizing the temperature of the cell, here we actively control Rb density with an electronic feedback loop. Clear Rb density stabilization is observed and the long-term drift in density is suppressed. Further demonstrations show that the temperature coefficient for Rb density in a vapor cell can be reduced more than 100 times when locked and the device's power consumption is only 50 mW. The device's locking dynamic range has also been investigated. Preliminary results show that the Rb density is well stabilized when the background density is five times higher (3.7x10^10 /cm3) than the set point reference density (0.6x10^10 /cm3). Active stabilization with this device is of high interest for portable cold-atom microsystems where large ambient temperature working ranges and low power consumption are required.