Distributed feedback lasing in dye-doped nanocomposite holographic transmission gratings

The application of holographic photocurable organic-inorganic nanocomposites is considered for the creation of permanent polymer microlasers with second-order distributed feedback (DFB) based on volume transmission diffraction gratings. The use of inorganic nanoparticles of size < 10 nm and refractive index (RI) >= 2 ensures the formation of volume periodic structures of high RI contrast and, correspondingly, high feedback efficiency combined with good optical quality. To fabricate a laser we have used a composite containing ZrO(2) nanoparticles dispersed in acrylate monomers, doped with Pyrromethene 567 laser dye. Transversal pumping of the gratings was performed by nanosecond laser pulses at 532 nm. The threshold, input-output and spectral characteristics of DFB lasers and their dependences on the RI contrast of the feedback structure have been investigated. The optimized values of RI contrast and concentration of the laser dye providing the lowest lasing threshold have been found. It was shown that the lasing wavelength can be tuned by varying the grating period as well as the nanoparticle concentration. Our first results demonstrate that nanocomposite gratings show promising potential for the cost-effective one-step fabrication of compact organic solid-state DFB lasers.