Lasing action from whispering-gallery modes in water microdroplets

A technique that may lead to even more powerful analytic tools has been reported by scientists at the University of California, Davis. The findings is believed to be the first observation of lasing based on the whispering-gallery modes in microdroplets that are formed in a microfabricated channel. They are dependent not only the resonant frequencies of its cavity but also on the intracavity gain-and-loss dynamics. Droplets were created by the scientists in a micromachined channel that injected water into a fast-flowing stream and then moved past two optical fibers. Synchronization of the experiment was assured through the scattered light. Results show that there were no signs of lasing initially but when boosted by adding glycerol, they saw the sought-after result.