Bichromatic laser emission from dipyrromethene dyes incorporated into solid polymeric media

Bichromatic laser emission from dipyrromethene-based solid-state dye lasers is reported. The dependence of this dual emission on different factors and its origin and causes are discussed in the light of different models proposed in the literature. Our experimental results indicate that the long-wavelength emission can be explained in terms of reabsorption/reemission effects and inhomogeneous broadening of the S-0-S-1 transition. The short-wavelength emission corresponds to the usual S-0-S-1 transition and dominates at low dye concentration. (c) 2007 American Institute of Physics.