Physics Procedia

Study and Optimization of CPT Resonance Parameters in 87 Rb/Ar/Ne Microcells Aimed for Application in Metrology

Y. Masian, A. V. Sivak, D. I. Sevostianov, Vitali V. Vassiliev, Vladimir L Velichansky

Published Jan 1, 2015• 5 citations

Abstract

The paper shows the presents results of studies of small-size rubidium cells with argon and neon buffer gases, produced by a patent pended technique of laser welding [Fishman et al. (2014)]. Cells were designed for miniature frequency standard. Temperature dependence of the frequency of the coherent population trapping (CPT) resonance was measured and used to optimize the ratio of partial pressures of buffer gases. The influence of duration and regime of annealing on the CPT-resonance frequency drift was investigated. The parameters of the FM modulation of laser current for two cases which correspond to the highest amplitude of CPT resonance and to the smallest light shifts of the resonance frequency were determined. The temperature dependences of the CPT resonance frequency were found to be surprisingly different in the two cases. A non-linear dependence of CPT resonance frequency on the temperature of the cell with the two extremes was revealed for one of these cases.

DOI: 10.1016/j.phpro.2015.08.359

Related papers

Optimization and reserach of Rb vapor cell of CPT atomic clock

Guo Jia-tai

In order to meeting the high stability of the coherent population trapping(CPT) atomic clock,we studied the relationship between CPT resonance frequency shift with pressure ratio of the buffer gases(argon and neon) through the 300μm thickness rubidium cell.When the total pressure of the buffer gases was 10 kPa,We found that the frequency shift rate varied along a bell shaped curve,and when the pressure ratio of Ar and Ne was 1:1.2 or 1.2:1,CPT resonance frequency drift rate was zero.

Laboratory ScienceJan 1, 20130 citations

Coherent population trapping on 87Rb atoms in small-size absorption cells with buffer gas

Ермак Сергей Викторович, Mikhail V. Petrenko, V. V. Semenov

Coherent population trapping (CPT) on 87 Rb atoms in neon atmosphere has been studied in small-size glass absorption cells under conditions of pumping with narrow-band laser radiation at the D 2 line of the main doublet. Parameters of the absorption signal have been measured in 3-mm-diameter cells at buffer gas (Ne) pressures varied within 200–400 Torr, cell temperatures within 65–120°C, and pumping radiation power densities within 30–400 μW/cm 2 . Optimum values of the buffer gas pressures, cell temperature, and pumping power are determined at which the short-term instability of the resonance line is at minimum. Orientational shifts of the CPT resonance signal in gas-filled cells and small-size cells with antirelaxation coating have been compared.

Technical Physics LettersFeb 1, 201611 citations

Coherent population trapping in small- and chip-scale 87Rb vapor cells with buffer gas

Ермак Сергей Викторович, V. V. Semenov, Mikhail V. Petrenko +1 more

The characteristics of coherent population trapping (CPT) signal were investigated in small-size glass vapor cells containing [Formula: see text]Rb and Ne buffer gas with narrow line-width laser pumping on D2 line. The parameters of CPT signals were measured using small-size vapor cells with Ne buffer gas pressure in the range of 200–400 Torr, cell temperature in the range of 65–120 [Formula: see text]C and the values of laser pumping power of 30–400 [Formula: see text]W/cm2. Optimal conditions, under which the minimal value of short-term instability of resonance line is achieved, were obtained in experiments. Orientation frequency shifts of CPT resonance using glass [Formula: see text]Rb vapor cells containing buffer gas and anti-relaxation coating were compared. CPT signals using vapor cells based on integrated technologies containing [Formula: see text]Rb in atmosphere of Ne were also investigated. The CPT signals with typical line widths of 2–3 kHz and signal-to-noise ratio of 1500 in 1 Hz bandwidth are observed, which allows one to provide relative frequency instability of 10[Formula: see text] at 100 s.

International Journal of Modern Physics Conference SeriesJan 1, 20163 citations

Investigation of coherent population trapping signals in 87Rb cells with buffer gas

M I Fedorov, Ермак Сергей Викторович, Mikhail V. Petrenko +2 more

Characteristics of CPT (coherent population trapping) signal are investigated in small-size glass vapor cells containing 87 Rb and Ne buffer gas with narrow linewidth laser pumping on D 2 line. Parameters of CPT absorption signals are measured using small-size vapor cells with Ne buffer gas pressure in range of 200-400 Torr, cell temperature in range of 65-120 °C and values of laser pumping power of 30-400 μW/cm 2 . Optimum conditions, under which the minimal value of short-term instability of resonance line is achieved, are obtained in experiments. CPT signals using vapor cells based on integrated technologies containing 87 Rb in atmosphere of Ne are also investigated. The CPT signals with typical linewidths of 2-3 kHz and signal-to-noise ratio of 1500 in 1 Hz bandwidth are observed, which allows one to provide relative frequency instability of 10 -11 at 100 s.

Journal of Physics Conference SeriesNov 1, 20162 citations

Coherent population trapping resonances in Cs–Ne vapor microcells for miniature clocks applications

Rodolphe Boudot, P. Dziuban, Madoka Hasegawa +4 more

We report the characterization of dark line resonances observed in Cs vapor microcells filled with a unique neon (Ne) buffer gas. The impact on the coherent population trapping (CPT) resonance of some critical external parameters such as laser intensity, cell temperature, and microwave power is studied. We show the suppression of the first-order light shift by proper choice of the microwave power. The temperature dependence of the Cs ground state hyperfine resonance frequency is shown to be canceled in the 77–80 °C range for various Ne buffer gas pressures. The necessity to adjust the Ne buffer gas pressure or the cell dimensions to optimize the CPT signal height at the frequency inversion temperature is pointed out. Based on such Cs–Ne microcells, we preliminary demonstrate a 852 nm vertical cavity surface emitted laser (VCSEL)-modulated based CPT atomic clock exhibiting a short term fractional frequency instability σy(τ)=1.5×10−10τ−1/2 until 30 s. These results, similar to those published in the literature by others groups, prove the potential of our original microcell technology in view of the development of high-performance chip scale atomic clocks.

Journal of Applied PhysicsJan 1, 201156 citations

Optimization of laser radiation for CPT-based miniature frequency standard

К. А. Баранцев, A. N. Litvinov, Evgeniy Popov +1 more

The present work is dedicated to optimization of the laser radiation parameters and optically thickness of the gas cell for improvement of short-term stability of quantum frequency standard based on coherent population trapping effect in the cell with 87Rb working gas and buffer gas. The effects associated with the optical density of the medium are investigated, such as laser spectrum distortion and appearance of the light shifts of the coherent population trapping resonance due to different absorption of frequency components.

European Frequency and Time ForumApr 1, 20162 citations