This paper reports a novel microfabrication method for rubidium (Rb) vapor cells with controlled nitrogen (N2) pressure, thereby enhancing the performance of miniaturized atomic clocks. An inkjet printing technique dispenses an aqueous solution of rubidium azide (RbN3) in 560 pL droplets onto a glass substrate, allowing precise control of the RbN3 quantity. A krypton fluoride (KrF) excimer laser with an energy of 38 mJ/mm2 irradiates RbN3, directly producing Rb and N2 in the cell, thereby optimizing the atomic clock functionality. This wafer-level fabrication technique not only provides precise N2 pressure control but also achieves frequency stability comparable to that of existing methods. The frequency stability, measured from the coherent population trapping (CPT) resonance, was estimated at 3×10−11 over an averaging time of 1 s. Further enhancements in temperature stability can be achieved by introducing an additional buffer gas like argon to cancel the frequency shift caused by the buffer gas.
Track ID:
7.3
Track Name:
IFCS: Microwave Frequency Standards & Applications
