Armstrong R L, Xie J G, Ruekgauer T E, Pinnick R G
Opt Lett. 1992 Jul 1;17(13):943-5. doi: 10.1364/ol.17.000943.
We report observations of lasing emission from liquid microdroplets of Fluorescein 548 dye in ethanol, seeded with submicrometer-sized fluorescent sol. An incident pump laser excites fluorescein dye molecules, which in turn couple energy to sol-dye molecules, generating lasing in the sol. The pump laser can also generate fluorescein lasing in the droplets, which may excite lasing in the sol. Other noteworthy findings include the absence of sol emission for larger sol and the presence of sol emission, even without any observable fluorescein emission, for smaller sol. All emissions are at wavelengths corresponding to morphology-dependent resonances of the droplet. Studies of the dependence of these emissions on pump laser intensity and sol concentration suggest that they are driven either by Förster energy transfer between fluorescein dye molecules and dye within the sol or by enhanced radiative transfer that occurs when fluorescein emission couples to morphology-dependent resonances of the droplet microcavity.
我们报告了在乙醇中含有亚微米级荧光溶质的548荧光素染料液体微滴产生激光发射的观测结果。入射泵浦激光激发荧光素染料分子，这些分子进而将能量耦合到溶质 - 染料分子，在溶质中产生激光。泵浦激光也可以在液滴中产生荧光素激光，这可能会激发溶质中的激光。其他值得注意的发现包括：对于较大的溶质，没有溶质发射；而对于较小的溶质，即使没有任何可观测到的荧光素发射，也存在溶质发射。所有发射都处于与液滴形态依赖共振相对应的波长。对这些发射与泵浦激光强度和溶质浓度依赖性的研究表明，它们要么是由荧光素染料分子与溶质内染料之间的Förster能量转移驱动，要么是由荧光素发射与液滴微腔形态依赖共振耦合时发生的增强辐射转移驱动。
