Experimental Demonstration of a Compact and High-Performance Laser-Pumped Rubidium Gas Cell Atomic Frequency Standard

Abstract

Abstract-The authors present a compact high-performance laser-pumped Rubidium atomic frequency standard exploiting the advantages of laser optical pumping for improved stability. The clock is based on an industrial Rb clock with the lamp assembly removed and optically pumped by light from a compact frequency-stabilized laser head. The modification of the buffer gas filling in the clock resonance cell reduces instabilities on medium-term timescales arising from the ac Stark effect and temperature variations. The frequency stability of the demonstrator clock was measured to be better than 4 × 10

Study of laser-pumped double-resonance clock signals using a microfabricated cell

“…Optics elements serve to control light polarization and intensity sent to the micro-fabricated clock cell. The micro-fabricated clock cell is placed in a compact magnetron-type cavity [13] sustaining a microwave field at the 6.834 GHz frequency of the 87 Rb ground-state hyperfine splitting. The cavity is surrounded by a solenoid used to produce a dc magnetic field to isolate the |F g = 1; m F = 0 →|F g = 2; m F = 0 clock transition.…”

High-performance laser-pumped rubidium frequency standard for satellite navigation

“…Here we show that our simple and compact, continuouswave (CW) laser-pumped double-resonance (DR) Rb clock stability outperforms that of LPCs standards up to 1000 s, and is comparable to coldatom portable clocks [3] or the SPHM, but from a physics package (PP) with volume of ,1 dm 3 only in our case. A previous laser-pumped Rb clock based on a magnetron-type cavity had a stability of s y ≃ 3 × 10 212 t 21/2 [7]. By increasing the cell diameter to 25 mm and redesign of the magnetron cavity, we improve on this clock stability while maintaining a very compact volume of the magnetron-type resonator.…”

ac Stark shift in double resonance and coherent population trapping in a wall-coated cell for compact Rb atomic clocks

“…This shift is one of the major limitations on the frequency stability of vapour-cell frequency standards ('Rb atomic clocks') [2]. The light-shift depends on the intensity and the optical frequency detuning of the pumping light and may be expressed (to first order and in local approximation) by the intensity light-shift coefficient α and the frequency light-shift coefficient β [3].…”

“…Here we report on our investigations on the light-shift in two possible schemes for Rb atomic clocks, shown in figure 1: double resonance (DR) interrogation (figure 1(a)) [3] and coherent population trapping (CPT), using the lin lin scheme ( figure 1(b)) [4]. For the DR interrogation, optical and microwave radiations are separately applied to the atoms, but simultaneously and in continuous mode, while for CPT, the microwave frequency is imprinted onto the light field by frequency modulation.…”