Department of Physics, Koç University, Istanbul, Turkey.
Opt Lett. 2013 May 15;38(10):1669-71. doi: 10.1364/OL.38.001669.
We report lasing in airborne, rhodamine B-doped glycerol-water droplets with diameters ranging between 7.7 and 11.0 μm, which were localized using optical tweezers. While being trapped near the focal point of an infrared laser, the droplets were pumped with a Q-switched green laser. Our experiments revealed nonlinear dependence of the intensity of the droplet whispering gallery modes (WGMs) on the pump laser fluence, indicating dye lasing. The average wavelength of the lasing WGMs could be tuned between 600 and 630 nm by changing the droplet size. These results may lead to new ways of probing airborne particles, exploiting the high sensitivity of stimulated emission to small perturbations in the droplet laser cavity and the gain medium.
我们报告了在直径为 7.7 至 11.0μm 的空气中，罗丹明 B 掺杂甘油-水液滴中的激光激射现象，这些液滴是使用光学镊子定位的。在被近红外激光束缚在焦点附近时，液滴被 Q 开关绿光激光泵浦。我们的实验揭示了液滴 whispering gallery 模式（WGM）强度与泵浦激光强度之间的非线性关系，表明了染料激光。通过改变液滴的大小，可以将激射 WGM 的平均波长在 600 至 630nm 之间调谐。这些结果可能会为探测空气中的粒子提供新的方法，利用受激辐射对液滴激光腔和增益介质中微小扰动的高灵敏度。
