Laser emission from dye doped microspheres produced on a chip

We fabricated, in a microfluidic channel, dye molecule doped microspheres with a remarkable size monodispersivity and interesting optical properties. The microspheres were obtained by spontaneous formation of droplets and photo-polymerization of a low viscosity and UV sensitive resin. By varying the channel width and the flow rate, microspheres of radius in the range of 20–80 μm could be obtained with a size dispersivity of about 2%. When pumped with a pulsed laser at 532 nm, multi-mode laser emissions around 610 nm were detected from R6G doped microspheres at a threshold of 16 μJ/mm2.