FRET-Tuned Resonant Random Lasing

We report the fabrication and characterization of a novel type of optical gain material. A biopolymeric matrix (DNA-lipid complex) doped with two families of organic dyes is combined with a strongly scattering medium. While the optical gain of the biopolymer complex is controlled via the FRET efficiency between the incorporated dyes, multiple scattering provides the necessary feedback to achieve lasing. This introduces two mechanisms to control the lasing wavelength: optical gain (via resonant energy transfer) and resonant scattering. In this way, an organic laser with a spectral tunability range over 40 nm is demonstrated.