Luo X, Eisaman M D, Gosnell T R
Opt Lett. 1998 Apr 15;23(8):639-41. doi: 10.1364/ol.23.000639.
A fluorozirconate glass doped with trivalent ytterbium ions has been laser cooled in vacuo from 298 to 277 K by optical pumping of the ions at 1015 nm. The cooling effect arises from anti-Stokes fluorescence of the laser-excited ions and by virtue of the near-unit fluorescence quantum efficiency for Yb(3+) in sufficiently pure solid hosts. The sample temperatures in the experiment are determined by measurement of the Yb(3+) emission spectrum; the value of the observed temperature change from room temperature as a function of pump wavelength is successfully explained in terms of a simple two-level model that includes the effect of optical saturation.
一种掺杂三价镱离子的氟锆酸盐玻璃在真空中通过在1015纳米处对离子进行光泵浦，从298K冷却到了277K。冷却效应源于激光激发离子的反斯托克斯荧光，并且得益于在足够纯净的固体基质中Yb(3+)近乎单位的荧光量子效率。实验中的样品温度通过测量Yb(3+)发射光谱来确定；从室温观察到的温度变化值作为泵浦波长的函数，依据包含光饱和效应的简单二能级模型得到了成功解释。
