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Laser Action (laser + action)
Selected AbstractsStructural Changes in the BODIPY Dye PM567 Enhancing the Laser Action in Liquid and Solid Media,ADVANCED FUNCTIONAL MATERIALS, Issue 16 2007I. García-Moreno Abstract In the search for more efficient and photostable solid-state dye lasers, newly synthesized analogs of the borondipyrromethene (BODIPY) dye PM567, bearing the polymerizable methacryloyloxypropyl group at position 2 (PMoMA) or at positions 2 and 6 (PDiMA), have been studied in the form of solid copolymers with methyl methacrylate (MMA). The parent dye PM567, as well as the model analogs bearing the acetoxypropyl group in the same positions, PMoAc and PDiAc, respectively, have been also studied both in liquid solvents and in solid poly(MMA) (PMMA) solution. Although in liquid solution PMoAc and PDiAc have the same photophysical properties as PM567, PDiAc exhibited a photostability up to 10 times higher than that of PM567 in ethanol under 310,nm-irradiation. The possible stabilization factors of PDiAc have been analyzed and discussed on the basis of the redox potentials, the ability for singlet molecular oxygen [O2(1,g)] generation, the reactivity with O2(1,g), and quantum mechanical calculations. Both PMoAc and PDiAc, pumped transversally at 532,nm, lased in liquid solution with a high (up to 58,%), near solvent-independent efficiency. This enhanced photostabilization has been also observed in solid polymeric and copolymeric media. While the solid solution of the model dye PDiAc in PMMA showed a lasing efficiency of 33,%, with a decrease in the laser output of ca.,50,% after 60,000 pump pulses (10,Hz repetition rate) in the same position of the sample, the solid copolymer with the double bonded chromophore, COP(PDiMA-MMA), showed lasing efficiencies of up to 37,%, and no sign of degradation in the laser output after 100,000 similar pump pulses. Even under the more demanding repetition rate of 30,Hz, the laser emission from this material remained at 67,% of its initial laser output after 400,000 pump pulses, which is the highest laser photostability achieved to date for solid-state lasers based on organic polymeric materials doped with laser dyes. This result indicates that the double covalent linkage of the BODIPY chromophore to a PMMA polymeric matrix is even more efficient than the simple linkage, for its photostabilization under laser operation. [source] Dye-Doped Polyhedral Oligomeric Silsesquioxane (POSS)-Modified Polymeric Matrices for Highly Efficient and Photostable Solid-State LasersADVANCED FUNCTIONAL MATERIALS, Issue 20 2009Roberto Sastre Abstract Here, the design, synthesis, and characterization of laser nanomaterials based on dye-doped methyl methacrylate (MMA) crosslinked with octa(propyl-methacrylate) polyhedral oligomeric silsesquioxane (8MMAPOSS) is reported in relation to their composition and structure. The influence of the silicon content on the laser action of the dye pyrromethene 567 (PM567) is analyzed in a systematic way by increasing the weight proportion of POSS from 1 to 50%. The influence of the inorganic network structure is studied by replacing the 8MMAPOSS comonomer by both the monofunctionalized heptaisobutyl-methacryl-POSS (1MMAPOSS), which defines the nanostructured linear network with the POSS cages appearing as pendant groups of the polymeric chains, and also by a new 8-hydrogenated POSS incorporated as additive to the polymeric matrices. The new materials exhibit enhanced thermal, optical, and mechanical properties with respect to the pure organic polymers. The organization of the molecular units in these nanomaterials is studied through a structural analysis by solid-state NMR. The domain size of the dispersed phase assures a homogeneous distribution of POSS into the polymer, thus, a continuous phase corresponding to the organic matrix incorporates these nanometer-sized POSS crosslinkers at a molecular level, in agreement with the transparency of the samples. The silicon,oxygen core framework has to be covalently bonded into the polymer backbone instead of being a simple additive and both the silica content and crosslinked degree exhibit a critical influence on the laser action. [source] Solid-State Lasers: (Materials for a Reliable Solid-State Dye Laser at the Red Spectral Edge) Adv.ADVANCED FUNCTIONAL MATERIALS, Issue 16 2009Funct. New photosensitive materials based on dye-doped polymeric matrices as active media in solid-state dye lasers allow highly efficient, stable, laser action, with fine tuning of the emitting wavelength from visible to NIR spectral region (575,750 nm) possible. These particular characteristics impelled the building of a prototype SSDL, which was compact, hazardless, versatile, and easy to handle. [source] Materials for a Reliable Solid-State Dye Laser at the Red Spectral EdgeADVANCED FUNCTIONAL MATERIALS, Issue 16 2009Inmaculada Garcia-Moreno Abstract In the search to extend the tuning range of solid-state dye lasers (SSDLs) to the red-edge spectral region, new photosensitive materials have been designed and synthesized based on six commercial dyes (sulforhodamine B, perylene red, rhodamine 640, LDS698, LDS722, and LDS730) incorporated into different linear, crosslinked, fluorinated, and sililated polymeric matrices. Under transversal pumping at 532,nm, these materials exhibit highly efficient, stable, as well as wavelength-tunable laser action from the visible-to-NIR spectral region (575,750,nm). The lasing performance of the materials doped with perylene and xanthene dyes is, to the best of our knowledge, the highest achieved to date for these chromophores when incorporated into organic, inorganic, or hybrid matrices. Regarding the LDS derivatives, this is the first time that laser action from these dyes in solid-state media is reported. These particular characteristics have impelled the building of the first prototype SSDL that is compact, versatile, and easy to handle. [source] Synthetic Strategies for Hybrid Materials to Improve Properties for Optoelectronic Applications,ADVANCED FUNCTIONAL MATERIALS, Issue 14 2008Olga García Abstract We report, for the first time to the best of our knowledge, a systematic study to relate the laser action from BODIPY dyes, doped into monolithic hybrid matrices, with the synthetic protocols of the final materials prepared via sol-gel. To this aim, the influence of both the hydrolysis time, increased in a controlled way, and the nature of the neutralization agent (pyridine, 3-amino-propyltriethoxy-silane (APS), N -[3-(trimethoxysilyl)propyl]-ethylene diamine (TSPDA), and N1 -[3-(trimethoxysilyl)propyl]- diethylene triamine (TSPTA) on the laser action of PM567, incorporated into hybrid matrices based on copolymers of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA), with methyltriethoxysilane (TRIEOS) as inorganic precursor, was analyzed. The presence of the amine-modified silane TSPDA as neutralization agent, which is able at the same time to be anchored to the inorganic network enhancing the inorganic-organic compatibility through the matrix interphase, and utilization of hydrolysis times lower than 10 minutes, increased significantly the lasing efficiency and photostability of dye. The extension of this study to the laser behavior of BODIPY dyes embedded in other different hybrid materials based on hydrolyzed-condensed copolymers of MMA with 3-(trimethoxysilyl)propyl methacrylate (TMSPMA) in a 1/1 volumetric proportion, validates the generalization of the above conclusions, which provide guides for the optimization of the synthesis of organic-inorganic hybrid materials with optoelectronic innovative applications independently of their composition. [source] Dye-Doped POSS Solutions: Random Nanomaterials for Laser EmissionADVANCED MATERIALS, Issue 41 2009Angel Costela New perspectives on disorder in photonic materials are opened up by polyhedral oligomeric silsesquioxanes (POSS) dispersed at a molecular level in dye-doped liquid and solid solutions. The optical homogeneity of these hybrid materials assures a coherent laser action, which is significantly enhanced by the stimulated emission multiply scattered by passive POSS centers. [source] Bottom-Up Fabrication of Photonic Defect Structures in Cholesteric Liquid Crystals Based on Laser-Assisted Modification of the Helix,ADVANCED MATERIALS, Issue 9 2007H. Yoshida Controlled fabrication of defect structures is performed in cholesteric liquid crystals by a laser-assisted polymerization process that induces a local elongation of the helix (see figure). Low-threshold laser action is observed from the photonic defect-mode observed within the selective reflection band. [source] A narrow band, green-red colour centre laser in LiF fabricated by femtosecond laser pulsesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 3 2007T. Kurobori Abstract Recent advances in high-intensity femtosecond (fs) laser pulses have made it possible to encode non-erasable functional micro-structures inside almost any type of photo-insensitive transparent materials. We focus our attention on bulk lithium fluoride (LiF) because of its broad emission band from the green-to-red spectral range under excitation of a single absorption band at about 450 nm. Here a room temperature, visible laser action in LiF from a distributed-feedback laser with embedded fine-pitched gratings written by fs pulses and from a laser-active colour centre laser with multilayer dielectric mirrors has been demonstrated. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Up to 30 times enhancement of deep UV emission at room temperature by prolonged excitation of localized exciton in NaCl:I crystalPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2009Ikuko Akimoto Abstract A material emitting DUV light at room temperature is promising for an application to a new laser action. We report the remarkable phenomena that deep ultra-violet (DUV) emission at 220 nm, so-called NE emission, in NaCl:I crystal is enhanced up to 30 times at room temperature by prolonged excitation of the localized exciton. Such an accumulated effect is kept even if the excitation is interuped for a few minutes but is completely reset by white light irradiation at room temperature. The phenomena are discussed considering thermal ionization of iodine anion by the VUV light excitation, trapping of dissociated electrons in hole centers and recombination of electrons and iodine hole centers. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | |||||||||||||