Mileti, Gaetano

2007, Mileti, Gaetano, Affolderbach, Christoph, Breschi, Evelina, Schori, Christian, Scherler, Patrick, Thomann, Pierre

2006-9-18, Giannini, R., Breschi, Evelina, Affolderbach, Christoph, Bison, G., Mileti, Gaetano, Herzig, H.P., Weis, Antoine

We established an experimental set-up that allows laser stabilization using the Doppler1 and sub-Doppler2,3 Dichroic Atomic Vapor Laser Locking (DAVLL) and the Saturated Absorption (SA) scheme. In this report we present comparative studies between Doppler and sub-Doppler DAVLL using heterodyne frequency stability measurements with an independently SA stabilized laser. Some major sources of frequency instability are discussed together with ways to improve the stability. Special focus is laid on the sub-Doppler DAVLL stabilization technique where a new approach for getting higher stability is introduced. In our measurements, the 87Rb D1 line was used as reference atomic line.

2006-6-27, Affolderbach, Christoph, Breschi, Evelina, Schori, Christian, Mileti, Gaetano

We present our development activities on compact Rubidium gas-cell atomic frequency standards, for use in space-borne and ground-based applications. We experimentally demonstrate a high-performance laser optically-pumped Rb clock for space applications such as telecommunications, science missions, and satellite navigation systems (e.g. GALILEO). Using a stabilised laser source and optimized gas cells, we reach clock stabilities as low as 1.5·10-12 τ-1/2 up to 103 s and 4·10-14 at 104 s. The results demonstrate the feasibility of a laser-pumped Rb clock reaching < 1·10-12 τ-1/2 in a compact device (<2 liters, 2 kg, 20 W), given optimization of the implemented techniques. A second activity concerns more radically miniaturized gas-cell clocks, aiming for low power consumption and a total volume around 1 cm3 , at the expense of relaxed frequency stability. Here miniaturized “chip-scale” vapour cells and use of coherent laser interrogation techniques are at the heart of the investigations.