Cold-atom clock based on a diffractive optic

We demonstrate a vapor cell atomic clock prototype based on continuous-wave (CW) interrogation and double-modulation coherent population trapping (DM-CPT) technique. The DM-CPT technique uses a synchronous modulation of polarization and relative phase of a bi-chromatic laser beam in order to increase the number of atoms trapped in a dark state, i.e. a non-absorbing state. The narrow resonance, observed in transmission of a Cs vapor cell, is used as a narrow frequency discriminator in an atomic clock. A detailed characterization of the CPT resonance versus numerous parameters is reported. A short-term frequency stability of 3.2 × 10 −13 τ −1/2 up to 100 s averaging time is measured. These performances are more than one order of magnitude better than industrial Rb clocks and comparable to those of best laboratory-prototype vapor cell clocks. The noise budget analysis shows that the short and mid-term frequency stability is mainly limited by the power fluctuations of the microwave used to generate the bi-chromatic laser. These preliminary results demonstrate that the DM-CPT technique is well-suited for the development of a high-performance atomic clock, with potential compact and robust setup due to its linear architecture. This clock could find future applications in industry, telecommunications, instrumentation or global navigation satellite systems.

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“…Thus, it is feasible to build a highly compact atomic clock. This method could also be applied to coldatom CPT clocks [24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

High-Performance Coherent Population Trapping Clock with Polarization Modulation

et al. 2017

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“…The invention of the laser 1 was a landmark for the scientific world and the ability to generate monochromatic, coherent light has opened avenues for research in many fields including atomic physics 2 , telecommunications 3,4 , and measurement science 5,6 . Its use in atomic physics precipitated the fields of laser spectroscopy 7,8 and laser cooling, which have led to applications in frequency and timing metrology [9][10][11] , magnetometry 12,13 and inertial sensing [14][15][16][17] .…”

Section: Introductionmentioning

confidence: 99%

A simple, powerful diode laser system for atomic physics

Daffurn,

Offer,

Arnold

2021

Preprint

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External-cavity diode lasers are ubiquitous in atomic physics and a wide variety of other scientific disciplines, due to their excellent affordability, coherence length and versatility. However, for higher power applications, the combination of seed lasers, injection-locking and amplifiers can rapidly become expensive and complex.Here we present a useful, high-power, single-diode laser design with specifications: >210 mW, 100 ms-linewidth (427 ± 7) kHz, >99% mode purity, 10 GHz mode-hop-free tuning range and 12 nm coarse tuning. Simple methods are outlined to determine the spectral purity and linewidth with minimal additional infrastructure. The laser has sufficient power to collect 10 10 87 Rb atoms in a single-chamber vapour-loaded magneto-optical trap. With appropriate diodes and feedback, the system could be easily adapted to other atomic species and laser formats.

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“…Here, we present a cubic high vacuum chamber, with 32 mm sides, and an integrated diffraction grating for magneto-optical trapping of atoms with a single input laser beam: a grating MOT (gMOT [31][32][33] ) vacuum cell (Fig. 1 a).…”

mentioning

confidence: 99%

“…1): good optical access, high vacuum pressures ≈ 10 −6 mbar, and a controllable source of Rb vapour. Our system is based around the gMOT architecture, where the grating properties 37,38 and gMOT phase space density [31][32][33]39 were fully characterised 40 in earlier work. A single input beam and a single 2 × 2 cm 2 in-vacuo micro-fabricated diffractive optic (patterned with e.g.…”

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confidence: 99%

“…Many cold atomic sensors operate with a measurement time in the 1-20 ms range 4,52-56 , which is already shorter than (and therefore largely unaffected by) our atomic collisional loss times. A concrete example of a device achievable using the cell presented here would be a compact cold-atom CPT clock 33 with repetition rate and Ramsey linewidth of 25 Hz. With 10 6 atoms loaded in 20 ms (Fig.…”

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confidence: 99%

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Stand-alone vacuum cell for compact ultracold quantum technologies

Burrow

Osborn

Boughton

et al. 2021

Applied Physics Letters

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Compact vacuum systems are key enabling components for cold atom technologies, facilitating extremely accurate sensing applications. There has been important progress towards a truly portable compact vacuum system, however size, weight and power consumption can be prohibitively large, optical access may be limited, and active pumping is often required. Here, we present a centilitre-scale ceramic vacuum chamber with He-impermeable viewports and an integrated diffractive optic, enabling robust laser cooling with light from a single polarization-maintaining fibre. A cold atom demonstrator based on the vacuum cell delivers 10 7 laser-cooled 87 Rb atoms per second, using minimal electrical power. With continuous Rb gas emission active pumping yields a 10 −7 mbar equilibrium pressure, and passive pumping stabilises to 3 × 10 −6 mbar, with a 17 day time constant. A vacuum cell, with no Rb dispensing and only passive pumping, has currently kept a similar pressure for more than 500 days. The passive-pumping vacuum lifetime is several years, estimated from short-term He throughput, with many foreseeable improvements. This technology enables wide-ranging mobilization of ultracold quantum metrology.

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Cold-atom clock based on a diffractive optic

Cited by 44 publications

References 51 publications

High-Performance Coherent Population Trapping Clock with Polarization Modulation

High-Performance Coherent Population Trapping Clock with Polarization Modulation

A simple, powerful diode laser system for atomic physics

Stand-alone vacuum cell for compact ultracold quantum technologies

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