Mileti, Gaetano

2010, Breschi, Evelina, Kazakov, G., Schori, Christian, Di Domenico, Gianni, Mileti, Gaetano, Litvinov, A., Matisov, B.

We report on light shift and broadening in the atomic-motion-induced Ramsey narrowing of dark resonances prepared in alkali-metal vapors contained in wall-coated cells without buffer gas. The atomic-motion-induced Ramsey narrowing is due to the free motion of the polarized atomic spins in and out of the optical interaction region before spin relaxation. As a consequence of this effect, we observe a narrowing of the dark resonance linewidth as well as a reduction of the ground states’ light shift when the volume of the interaction region decreases at constant optical intensity. The results can be intuitively interpreted as a dilution of the intensity effect similar to a pulsed interrogation due to the atomic motion. Finally the influence of this effect on the performance of compact atomic clocks is discussed.

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

2009, Breschi, Evelina, Mileti, Gaetano, Kazakov, G., Matisov, B., Lammegger, R., Windolz, L.

We have investigated the lin∥lin CPT signal in the 87Rb D1 manifold when the atoms are contained in low pressure buffer gas cells. We predict the achievable clock frequency stability, basing our considerations on the signal-to-noise measurements. We show that a short-term stability of about 2 · 10-11 τ1/2 may be reached in a compact system using a modulated VCSEL, this value is mainly limited by the detection noise level and can be improved up to a factor 4 by using high frequency phase sensitive detection. Under the same experimental condition a challenging short-term stability of 1-3 · 10-13 τ1/2 can be achieved by using the PL ECDLs.

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.

2009, Breschi, Evelina, Kazakov, G., Lammegger, R., Matisov, B., Windholz. L., Mileti, Gaetano

We evaluate the influence of 2 types of laser sources with different spectral profiles on the performance of vapor cell atomic clocks based on lin

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.