Trapping lasers in a laser trap: microscopic lasers for sensing and tagging of live cells

Whispering gallery mode microlasers are exquisite sensors that can quantitatively report their size as well as any shifts in the refractive index of their environment via a spectral change. By inserting such microlasers into live cells, my team tags and tracks individual cells in large cell populations over extended periods of time. We have also developed this technology further to perform in vitro and in vivo sensing, e.g. the mapping forces in fruit fly larvae. Now, using laser-based optical trapping, we show that we can trap and manipulate our microlasers. This allows for more targeted delivery of lasers to individual cells as well as for fine spatial control of the volume over which microlasers measure local refractive index.