Laser cooling ytterbium doped silica by 67 K from ambient temperature.
Opt Express
; 32(3): 3660-3672, 2024 Jan 29.
Article
em En
| MEDLINE
| ID: mdl-38297582
ABSTRACT
Laser cooling of a 5 cm long, 1 mm diameter ytterbium doped (6.56×1025 ions/m3) silica rod by 67 K from room temperature was achieved. For the pump source, a 100 W level ytterbium fiber amplifier was constructed along with a 1032 nm fiber Bragg grating seed laser. Experiments were done in vacuum and monitored with the non-contact differential luminescence thermometry method. Direct measurements of the absorption spectrum as a function of temperature were made, to avoid any possible ambiguities from site-selectivity and deviations from McCumber theory at low temperature. This allowed direct computation of the cooling efficiency versus temperature at the pump wavelength, permitting an estimated heat lift of 1.42 W/m as the sample cooled from ambient temperature to an absolute temperature of 229 K.
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MEDLINE
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En
Ano de publicação:
2024
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Article