Distributed feedback lasing in dye-doped nanocomposite holographic transmissiongratings

Abstract

The application of holographic photocurable organic–inorganic nanocomposites is considered forthe 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 refractiveindex (RI) ≥ 2 ensures the formation of volume periodic structures of high RI contrastand, correspondingly, high feedback efficiency combined with goodoptical quality. To fabricate a laser we have used a composite containingZrO2 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 theirdependences on the RI contrast of the feedback structure have been investigated. Theoptimized values of RI contrast and concentration of the laser dye providing the lowestlasing threshold have been found. It was shown that the lasing wavelength can be tuned byvarying the grating period as well as the nanoparticle concentration. Our firstresults demonstrate that nanocomposite gratings show promising potential forthe cost-effective one-step fabrication of compact organic solid-state DFB lasers.