Laser-pumped high-performance compact gas-cell Rb standard with < 3×10−13 τ−1/2 stability

We demonstrate a high-performance laser-pumped rubidium-cell atomic frequency standard exhibiting a short-term stability of <; 3×10^-13 τ^-1/2. The key components of this standard are a Rb vapor cell of 25mm diameter and a newly developed compact microwave resonator cavity. The overall volume of the clock´s physics package - including the frequency-stabilized laser head and physics package - is <; 3 liters, which shows the potential of this compact clock for future portable applications.