A multicolor microfluidic droplet dye laser with single mode emission

A digital microfluidic dye laser that integrates a Fabry-Perot cavity with two fiber-based mirrors is shown to exhibit a single mode emission. In addition, fast switching is achieved via the alternation of droplet streams that contain two different dyes. Single-longitudinal-mode emission is observed for each dye wavelength (at 565 and 586 nm) with a linewidth narrower than 0.12 nm. This system appears thus well suited for on-chip spectroscopy and flow cytometry. (C) 2011 American Institute of Physics. [doi:10.1063/1.3565242]