Knall Jennifer, Vigneron Pierre-Baptiste, Engholm Magnus, Dragic Peter D, Yu Nanjie, Ballato John, Bernier Martin, Digonnet Michel J F
Opt Lett. 2020 Mar 1;45(5):1092-1095. doi: 10.1364/OL.384658.
For the first time, to the best of our knowledge, laser cooling is reported in a silica optical fiber. The fiber has a 21-µm diameter core doped with 2.06 wt.% ${{\rm Yb}^{3 + }}$Yb and co-doped with ${{\rm Al}_2}{{\rm O}_3}$AlO and ${{\rm F}^ - }$F to increase the critical quenching concentration by a factor of 16 over the largest reported values for the Yb-doped silica. Using a custom slow-light fiber Bragg grating sensor, temperature changes up to $ - {50};{\rm mK}$-50mK were measured with 0.33 W/m of absorbed pump power per unit length at 1040 nm. The measured dependencies of the temperature change on the pump power and the pump wavelength are in excellent agreement with predictions from an existing model, and they reflect the fiber's groundbreaking quality for the radiation-balanced fiber lasers.
据我们所知，首次报道了在二氧化硅光纤中实现激光冷却。该光纤的纤芯直径为21μm，掺杂了2.06 wt.%的Yb³⁺，并共掺杂了Al₂O₃和F⁻，以使临界猝灭浓度比报道的最大掺镱二氧化硅值提高16倍。使用定制的慢光光纤布拉格光栅传感器，在1040nm处，每单位长度吸收0.33W/m的泵浦功率时，测量到温度变化高达-50mK。测得的温度变化对泵浦功率和泵浦波长的依赖性与现有模型的预测结果非常吻合，这反映了该光纤对于辐射平衡光纤激光器具有开创性的品质。
