Miletic, Danijela

2012-9-21, Miletic, Danijela, Affolderbach, Christoph, Hasegawa, M, Boudot, R, Gorecki, C, Mileti, Gaetano

We report on studies on the light-shift in cae-sium miniature atomic clocks based on coherent populationtrapping (CPT) using a micro-fabricated buffer-gas cell(MEMS cell). The CPT signal is observed on the Cs D1-lineby coupling the two hyperfine ground-state Zeeman suble-vels involved in the clock transition to a common excitedstate, using two coherent electromagnetic fields. These lightfields are created with a distributed feedback laser and anelectro-optical modulator. We study the light-shift phe-nomena at different cell temperatures and laser wavelengthsaround 894.6 nm. By adjusting the cell temperature, con-ditions are identified where a miniature CPT atomic clockcan be operated with simultaneously low temperaturecoefficient and suppressed light-shift. The impact of thelight-shift on the clock frequency stability is evaluated.These results are relevant for improving the long-term fre-quency stability of CPT-based Cs vapour-cell clocks.

2010-9-20, Miletic, Danijela, Affolderbach, Christoph, Mileti, Gaetano

In this paper we present our spectroscopic studies on Coherent Population Trapping (CPT) in micro-fabricated Caesium cells and our evaluation of its application in miniature atomic frequency standards (atomic clocks). We observe the CPT signal on the Cs D1-line by coupling two hyperfine ground-state Zeeman sub-levels to a common excited state using two coherent electromagnetic fields created with a modulated DFB laser. Contrarily to double resonance, CPT does not require any microwave cavity, which should facilitate the miniaturization of a future atomic clock device. We study and report here on the light shift phenomena at different cell temperatures and laser wavelength. We also present resonance shifts due to cell temperature variations and clock frequency stability measurements. To the best of our knowledge, this article is the first report on light shift with Cs D1 line in a CPT vapour-cell atomic clock.

2009, Affolderbach, Christoph, Gruet, Florian, Miletic, Danijela, Mileti, Gaetano

We report on our development of a compact and high-performance laser-pumped Rubidium atomic frequency standard. The clock design is based on optical-microwave double-resonance using cw optical pumping, and a physical realization as simple as possible. Main development goals are a short-term instability of ≤ 6 × 10-13 τ-1/2 and a flicker floor of ≤ 1 × 10-14 up to one day. Here we discuss our approaches for controlling the clock's main physical parameters in view of optimized frequency stability.