Microfabricated chip-scale rubidium plasma light source for miniature atomic clocks

Abstract

Abstract-We present the microfabrication and characterization of a low-power, chip-scale Rb plasma light source, designed for optical pumping in miniature atomic clocks. A dielectric barrier discharge (DBD) configuration is used to ignite a Rb plasma in a micro-fabricated Rb vapor cell on which external indium electrodes were deposited. The device is electrically driven at frequencies between 1 and 36 MHz, and emits 140 µW of stable optical power while coupling less than 6 mW of electrical power to the discharge cell. Optical powers of up to 15 and 9 µW are emitted on the Rb D2 and D1 lines, respectively. Continuous operation of the light source for several weeks has been demonstrated, showing its capacity to maintain stable optical excitation of Rb atoms in chip-scale double-resonance atomic clocks.

Optical pumping in a microfabricated Rb vapor cell using a microfabricated Rb discharge light source

“…Their splitting and the ratio of their resonant frequencies also matched the ratio of their gyromagnetic ratios (c 87 /c 85 ). The power stability of the light emitted by the microfabricated discharge light source is on the level of few percent over the timescale of few minutes to few hours 25,29 resulting in a reproducibility of the DR signals on the level of the noise in Fig. 4 between consecutive scans.…”

“…Recently, our teams have developed a miniature microfabricated 1 Â 1 Â 0.3 cm 3 Rb dielectric barrier discharge (DBD) light source 25 as an alternative to a VCSEL light source and to extend the inherent advantages of a Rb discharge lamp to miniature clocks and magnetometers. This light source was also characterized with respect to various cell and drive parameters to minimize its power consumption and increase D-line emission.…”

Double-resonance in alkali vapor cells for high performance and miniature atomic clocks

“…The second line concerns the development of a microfabricated Rb discharge lamp, as an alternative to laser diodes for optical pumping in miniature DR atomic clocks [32]. This approach bears the promise of a much simpler and cheaper micro-fabricated light source than semiconductor lasers.…”

Reliability characteristics of microfabricated Rb mini-lamps for optical pumping in miniature atomic clocks and magnetometers

“…Rubidium discharge lamps have been widely used for developing compact (100-1000 cm 3 ) double-resonance atomic clocks, where they are used for optically pumping the Rb atoms in a reference cell for high precision time keeping (clock uncertainty <10 -12 ) through microwave interrogation techniques. There has recently been a lot of interest in developing miniature (<few cm 3 ) clocks, to improve the performance of highly portable applications such as GPS receivers, but the predominantly available inductively-coupled glass-blown Rb discharge lamps could not be scaled down for use here, due to their high-power consumption (several watts) and non-planar high-volume geometry.…”

“…There has recently been a lot of interest in developing miniature (<few cm 3 ) clocks, to improve the performance of highly portable applications such as GPS receivers, but the predominantly available inductively-coupled glass-blown Rb discharge lamps could not be scaled down for use here, due to their high-power consumption (several watts) and non-planar high-volume geometry. Laser diodes (VCSELs) were used instead as they are compact and power efficient but they have several undesirable characteristics including a strong temperature dependence of the output wavelength, and ageing effects.…”