Laser cooling of a potassium–argon gas mixture using collisional redistribution of radiation

Saß, Anne; Vogl, Ulrich; Weitz, Martin

doi:10.1007/s00340-011-4401-y

Cited by 12 publications

(15 citation statements)

References 26 publications

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“…A process of collisional redistribution of radiation [76,77] was demonstrated to cool dense gases by 120 K, starting at ∼500 K [78]. Spontaneous Brillouin scattering has been utilized to cool targeted vibrational modes of a microresonator [79].…”

Section: Introductionmentioning

confidence: 99%

Cryogenic optical refrigeration

et al. 2012

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Doc. ID 157833)We review the field of laser cooling of solids, focusing our attention on the recent advances in cryogenic cooling of an ytterbium-doped fluoride crystal (Yb 3+ :YLiF 4 ). Recently, bulk cooling in this material to 155 K has been observed upon excitation near the lowest-energy (E4-E5) crystal-field resonance of Yb 3+ . Furthermore, local cooling in the same material to a minimum achievable temperature of 110 K has been measured, in agreement with the predictions of the laser cooling model. This value is limited only by the current material purity. Advanced material synthesis approaches reviewed here would allow reaching temperatures approaching 80 K. Current results and projected improvements position optical refrigeration as the only viable all-solid-state cooling approach for cryogenic temperatures.

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Section: Introductionmentioning

confidence: 99%

Cryogenic optical refrigeration

et al. 2012

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“…[1][2][3] In fact, we could so far not observe a measurable attenuation of the resonant laser beam crossing the sample cell. WE expect that the yield can be substantially increased by increasing the laser power with a corresponding increase of the laser beam diameter at the target surface in order to keep the laser intensity fixed.…”

Section: Discussionmentioning

confidence: 82%

“…2, 3 The cooling cycle proceeds in three steps: first, the atomic transition of the cooled species is shifted towards lower energies by a collision with a buffer-gas atom. At this moment, the atom absorbs a photon from a laser beam that is red-detuned from the undisturbed atomic transition.…”

Section: Collisional Redistribution Laser Cooling Is a Novel Techniqumentioning

confidence: 99%

“…Efficient cooling is thus possible at high initial temperature T 0 and requires a large rate of atomic collisions that can be achieved at a high buffer gas pressure p. It is also important that the red-detuned laser radiation is strongly absorbed by the gas, which requires a strong collision broadening of the atomic spectral line and a high number density of the absorbing atoms. The cooling effect was demonstrated [1][2][3][4] in alkali-metal (Rb, K) vapors mixed with different noble gases (He, Ar) at the initial temperature of 500-700 K and the buffer gas pressure of 100-200 bar. Under these conditions, the sample is optically dense even at the used detunings of 10-20 nm with respect to the wavelength of the resonant transition of the alkali atom.…”

Section: Collisional Redistribution Laser Cooling Is a Novel Techniqumentioning

confidence: 99%

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Towards redistribution laser cooling of molecular gases: production of candidtate molecules SrH by laser ablation

et al. 2013

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Laser cooling by collisional redistribution of radiation has been successfully applied in the past for cooling dense atomic gases. Here we report on progress of work aiming at the demonstration of redistribution laser cooling in a molecular gas. The candidate molecule strontium monohydride is produced by laser ablation of strontium dihydride in a pressurized noble gas atmosphere. The composition of the ablation plasma plume is analyzed by measuring its emission spectrum. The dynamics of SrH molecular density following the ablation laser pulse is studied as a function of the buffer gas pressure and the laser intensity.

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“…Interestingly it has been shown recently that this ratio can be tremendously improved using excited molecular states (exciplexes) of Alkali-rare gas molecules as e.g. Rb-Ar or K-Ar [16]. In this case the incoming laser light can be up-converted by a few percent allowing to increase the efficiency per scattering event by several orders of magnitude.…”

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confidence: 99%

Laser refrigeration of gas filled hollow-core fibres

et al. 2019

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We theoretically study prospects and limitations of a new route towards macroscopic scale laser refrigeration based on exciplex-mediated frequency up-conversion in gas filled hollow-core fibres. Using proven quantum optical rate equations we model the dynamics of a dopant-buffer gas mixture filling an optically pumped waveguide. In the particular example of alkali-noble gas mixtures, recent high pressure gas cell setup experiments have shown that efficient kinetic energy extraction cycles appear via the creation of transient exciplex excited electronic bound states. The cooling cycle consists of absorption of lower energy laser photons during collisions followed by blue-shifted spontaneous emission on the atomic line of the alkali atoms. For any arbitrary dopant-buffer gas mixture, we derive scaling laws for cooling power, cooling rates and temperature drops with varying input laser power, dopant and buffer gas concentration, fibre geometry and particularities of the exciplex ground and excited state potential landscapes.

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Laser cooling of a potassium–argon gas mixture using collisional redistribution of radiation

Cited by 12 publications

References 26 publications

Cryogenic optical refrigeration

Cryogenic optical refrigeration

Towards redistribution laser cooling of molecular gases: production of candidtate molecules SrH by laser ablation

Laser refrigeration of gas filled hollow-core fibres

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