The heart of the miniature atomic clock began to beat
Employees of the Laboratory of Frequency Standards of the Lebedev Physical Institute are working on the creation of a new generation of small-sized atomic clocks. In particular, a miniature quantum discriminator has now been developed – the “heart” of future highly stable atomic clocks. Despite the small volume of the quantum discriminator – no more than 10 cm10-12 – the atomic clock created at FIAN will be so accurate that it will accumulate a deviation of only one millionth of a second per day.
The relative instability of some of the world’s most accurate atomic frequency and time standards (cesium fountains) reaches 10-16… These clocks set the time in national metrology laboratories. Lower precision clock – 10-13 – provide accurate time measurement on navigation satellites, for example, on GPS and GLONASS satellites. In most mass applications on Earth, such a high accuracy is not needed, 10-eleven – ten-nine… Thus, precision crystal oscillators currently being produced have a relative long-term frequency instability of about 10-eleven – ten-nine per day. Traditional rubidium standards with a volume of the order of a thousand cubic centimeters, and weighing up to kilograms, have an output frequency instability of 10-12…
Physicists from the Lebedev Physical Institute (Ph.D. Vladimir Velichansky, Researcher Vitaly Vasiliev, Ph.D. Sergei Zibrov, and graduate students Olga Kozlova and Alexander Sivak) in collaboration with the Institute of Laser Physics SB RAS (a specifically, theorists V.I. Yudin, D.Sc. and V.A.Taichenachev, D.Sc.-eleven, combining it with the diminutiveness of the device. The “pendulum” of the clock being developed is the cesium atom, in which the mutual orientation of the moments of the nucleus and the electron changes approximately 10 billion times per second. Such watches are designed for mass use and will replace precision quartz oscillators, at least an order of magnitude superior to them in long-term stability with less volume and power consumption. It is expected that the volume of the watch will not exceed 50 cm10-12, and the power required for consumption is 0.3 W.
A prototype of a quantum discriminator with a volume of 10 cm assembled at FIAN3
“The dimensions of the atomic frequency and time standards of the previous generation were limited by the wavelength of the resonant microwave field interacting with the atomic medium. Therefore, until recently it was considered impossible to create a device with characteristic dimensions less than a few centimeters. However, thanks to the discovery in the 70s of the effect Now, instead of probing the metrological resonance of atoms with an optical and microwave field, two optical fields are used, and the need for a bulky microwave resonator has disappeared. miniaturization “- explains the researcher of the Laboratory of Frequency Standards Vitaly Vasiliev…
“For optical excitation, miniature lasers are now used instead of gas-discharge lamps, which makes it possible to reduce the dimensions of atomic standards with a relative instability of about 10-11 times tens of times, reduce their power consumption and cost. This will make it possible to embed atomic clocks in portable devices”, – says graduate student Alexander Sivak…
The area is very relevant – the development of such atomic clocks is also actively carried out in the USA, France, China, Israel, Canada, Switzerland.
“Science is international and this project confirms this especially clearly. CPT effect was discovered in Italy, in Canada we were the first to carry out purely optical sounding of microwave resonance, we at FIAN in 1991 were the first to use highly coherent semiconductor lasers to register the effect, in Germany we demonstrated the possibility of using the smallest type semiconductor lasers – lasers with a vertical resonator.Already in this century, the National Institute of Standards and Technology (USA) and powerful companies (Honeywell, Symmetricom, Kernko) began to develop technology for the mass production of small-sized atomic clocks. hours, therefore, it is in this direction that our main efforts are now concentrated. As for the physics of the effect, our work has been carried out at the world level “, – tells the leading researcher of the Laboratory of Frequency Standards Vladimir Velichansky.
Simultaneously with the development of the corresponding compact electronic circuit, FIAN is working on further reducing the size of the discriminator and on new technologies for creating its main units. The completion of the experimental design is scheduled for 2012, after which one of the Russian companies will begin to organize in Russia the serial production of precise and small-sized atomic clocks. A commercially available and available device will significantly increase the speed of consumer navigation devices, develop anti-jamming broadband communications, apply new location methods, and much more.