Affolderbach, Christoph

2018-6-7, Pellaton, Matthieu, Affolderbach, Christoph, Mileti, Gaetano, Skrivervik, A.K., Ivanov, A.E., Debogovic, T., de Rijk, E.

The authors present the realisation and characterisation of an additively manufactured (AM) microwave resonator cavity for double-resonance (DR) vapour-cell atomic clocks. The design of the compact microwave cavity is based on the loop-gap resonator approach, previously demonstrated for conventionally-machined aluminium components. In the present study, the resonator is fabricated by AM using a metal-coated polymer. A resonance frequency at the desired 6.835 GHz rubidium atomic frequency is obtained. When employed in an atomic clock setup, the AM cavity enables a DR signal of <;500 Hz linewidth and of nearly 20% contrast, thus fulfilling the stringent requirements for DR atomic clocks. A clock short-term stability of 1 × 10 -12 τ -1/2 is demonstrated, comparable to state-of-the-art clock performances.

, Bandi Nagabhushan, Thejesh, Affolderbach, Christoph, Mileti, Gaetano

We have realized and studied a rubidium atomic frequency standard based on a paraffin-coated cell, exhibiting a short-term frequency stability <3 × 10⁻¹² τ^−1/2 between τ = 1 and 100 s. Characterization of the wall-coating is performed by measuring the T₁and T₂ relaxation times. Perturbations of the medium- to long-term clock stability, due to variations in the laser-intensity, laser frequency, the microwave power shift, and the shifts due to temperature variations are measured and analyzed. A method for reducing the intensity light-shift by detuning the laser frequency and the resulting improvement in clock stability is demonstrated. This work is of relevance for further improvements on Rb cell standards using anti-relaxation wall-coating technology.