Optical cooling of a Yb-doped alumino-phosphosilicate fiber in air by -250â
mK.
Opt Lett
; 49(16): 4501-4504, 2024 Aug 15.
Article
em En
| MEDLINE
| ID: mdl-39146088
ABSTRACT
Recent progress in the fabrication of Yb-doped silicate fibers with low concentration quenching and low background absorption loss has led to the demonstration of anti-Stokes-fluorescence cooling in several aluminosilicate compositions. This breakthrough is critical to combat deleterious thermal effects due to the quantum defect in fiber lasers and amplifiers. Since cooling efficiencies remain low (1-2.7%), it is paramount to engineer compositions that improve this metric. We report a silica fiber with a core glass heavily doped with aluminum and phosphorus that sets, to our knowledge, a few new records. This few-mode fiber (16-µm core) was cooled in air by -0.25â
K from room temperature with â¼0.5â
W of 1040-nm power. The measured cooling efficiency is 3.3% at low pump power and 2.8% at the power that produced maximum cooling. The critical quenching concentration inferred from the measured dependence of cooling on pump power and careful calibration of the pump absorption and saturation is 79â
wt.%. The inferred background absorption loss is 15â
dB/km. Together with the fiber's average Yb concentration of 4.2â
wt.%, these metrics rank among the best reported in a silica glass.
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01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article