Cavity-enhanced effects with silica microspheres immersed in superfluid helium
Valérie Lefèvre-Seguin, François Treussart, Vladimir S. Ilchenko +4 more
Silica microspheres behave as efficient optical microresonators when small-volume whispering-gallery modes (WGMs) are used. We have realized a cryogenic set-up to work with microspheres immersed in a superfluid helium bath. Quality factors up to 109 have been obtained at 2 K. In this environment, we have been able to observe a dispersive bistable behavior of the WGM resonances, due to the weak intrinsic Kerr optical nonlinearity of silica, with a threshold power of 10 (mu) W only. This result opens the way to the realization of thresholdless microlaser, based on a rare-earth doped silica microsphere and to other Cavity-QED projects with microspheres at low temperatures.
Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Feb 25, 1999•0 citations