Low-Power Chip-Scale Rubidium Plasma Light Source for Miniature Atomic Clocks

We present the development, testing and characterization of a low-power chip-scale Rubidium (Rb) plasma light source designed to serve for optical pumping in miniature atomic clocks. The technique used is electrodeless capacitively coupled plasma (CCP) discharge, driven in a microfabricated Rb vapor cell. The device is electrically driven at frequencies between 1 and 36 MHz to emit 140 μW of stable optical power while coupling < 6 mW of electrical power to the discharge cell. To our knowledge this is the first reported Rb plasma emitted from a chip-scale device.