Optimization of a chip-scale Rb plasma discharge light source: Effects of RF drive frequency and cell impedance

We report on the performance improvements achieved on our previously demonstrated proof-of-concept chip-scale dielectric barrier discharge (DBD) Rb lamp [1], (1) with change in the plasma regime of operation by changing RF drive frequency and (2) with an improved electrode design, for optical pumping in a chip-scale Double-Resonance (DR) atomic clock. Our realized microfabricated planar DBD Rb lamp now has externally deposited Al electrodes, allowing for efficient power coupling to the discharge volume and was tested at different RF drive frequencies ranging from 2 MHz to 500 MHz. Currently the light source can emit up to 380 μW of optical power on the Rb D2 line depending on input conditions.