Home About us Contact
|
Home About us Contact | ||
|
|
||
Solid-state Lasers (solid-state + laser)
Selected AbstractsGlass-Forming Cholesteric Liquid Crystal Oligomers for New Tunable Solid-State LaserADVANCED MATERIALS, Issue 8 2010Seiichi Furumi A new potential utility of glass-forming cholesteric liquid crystal (G-CLC) oligomers for application in tunable solid-state laser is presented. The G-CLC is capable of tuning the photonic band gaps (PBGs) by way of the annealing temperature and preserving the tuned PBGs by a subsequent supercooling treatment. This G-CLC film enables the facile fabrication of a continuously gradated PGB structure and, thus, the continuous tuning of a single laser-emission peak (see figure). [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] Glass-Forming Cholesteric Liquid Crystal Oligomers for New Tunable Solid-State LaserADVANCED MATERIALS, Issue 8 2010Seiichi Furumi A new potential utility of glass-forming cholesteric liquid crystal (G-CLC) oligomers for application in tunable solid-state laser is presented. The G-CLC is capable of tuning the photonic band gaps (PBGs) by way of the annealing temperature and preserving the tuned PBGs by a subsequent supercooling treatment. This G-CLC film enables the facile fabrication of a continuously gradated PGB structure and, thus, the continuous tuning of a single laser-emission peak (see figure). [source] Edge-pumped asymmetric Yb:YAG/YAG thin disk laserLASER PHYSICS LETTERS, Issue 10 2007Q. Liu Abstract An edge-pumping scheme for a quasi-three-level solid-state laser using asymmetric crystal is reported. The scheme uses a thin disk laser configuration with the pump light incident from disk edges. The pump light propagates through the disk along the zigzag path and repeatedly passes the gain medium, thus improving the pump uniformity and absorption efficiency. A maximum output power of over 123 W was achieved from an edge-pumped composite Yb:YAG/YAG thin disk laser, with slope efficiency of 34.8% and beam quality M2 , 20. (© 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] A c-cut Nd:GdVO4 solid-state laser passively Q-switched with Co2+:LaMgAl11O19 lasing at 1.34 µmLASER PHYSICS LETTERS, Issue 8 2007H.-J. Qi Abstract We investigated a high power diode-laser pumped passively Q-switched c-cut Nd:GdVO4 solid-state laser, lasing at 1.34 µm, with a Co2+:LaMgAl11O19 saturable absorber. With the optimum output coupler transmission T = 5.5% and pump power of 11.5 W, the static output power of 3.01 W was obtained. The passively Q-switching operation with Co:LMA (initial transmission T0 = 90%) as saturable absorber, shows that the shortest output pulse width, the highest output power, the highest pulse repetition and the highest pulse peak power were 32 ns, 266 mW, 277 kHz, and 187 W, respectively. (© 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] 20-W average power, high repetition rate, nanosecond pulse with diffraction limit from an all-fiber MOPA systemMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2008Songtao Du Abstract In this article, we report an all-fiber master oscillator power amplifier (MOPA) system, which can provide high repetition rate and nanosecond pulse with diffraction-limit. The system was constructed using a (2 + 1) × 1 multimode combiner. The Q-Switched, LD pumped Nd:YVO4 solid-state laser was used as master oscillator. The 976-nm fiber-coupled module is used as pump source. A 10-m long China-made Yb3+ -doped D-shape double-clad large-mode-area fiber was used as amplifier fiber. The MOPA produced as much as 20-W average power with nanosecond pulse and near diffraction limited. The pulse duration is maintained at about 15 ns during 50,175 kHz. The system employs a simple and compact architecture and is therefore suitable for the use in practical applications such as scientific and military airborne LIDAR and imaging. Based on this system, the amplification performances of the all-fiber amplifier is investigated. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2546,2549, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23770 [source] Synthesis of Nd-YAG material by citrate-nitrate sol-gel combustion route,ADVANCED ENGINEERING MATERIALS, Issue 4 2007L. Costa Polycrystalline, Neodymium doped, yttrium aluminum garnet Nd:YAG is a functional materials for solid-state lasers. The synthesis of Nd:YAG powders requires a strict control of the precursor reactivity and composition. Sol-gel citrate-based methods increase the chemical homogeneity and reactivity of the precursor powder. Calcination performed around 900,°C leads to the formation of pure YAG phase at temperatures much lower than the temperature required for the solid-state reaction (1600,°C). [source] Boosting the Non Linear Optical Response of Carbon Nanotube Saturable Absorbers for Broadband Mode-Locking of Bulk LasersADVANCED FUNCTIONAL MATERIALS, Issue 12 2010W. B. Cho Abstract Single-walled carbon-nanotube absorbers are experimentally demonstrated for laser mode-locking. A saturable absorber device is used to mode-lock three different bulk solid-state lasers in a 500,nm-wide wavelength interval. The devices exhibit a low saturation fluence of <10,µJ cm,2, low scattering losses, and an exceptionally rapid relaxation, with time constants reaching <100 fs. The latter two properties are explained by a decreased curling tendency and increased tube-to-tube interactions of the nanotubes, respectively. These properties are the result of an optimized manufacturing procedure in combination with the use of a starting material with a higher microscopic order. The decreased scattering enables universal use of these devices in bulk solid-state lasers, which tend to be highly sensitive against non-saturable device losses as caused by scattering. The favorable saturable absorption properties are experimentally verified by mode-locking the three lasers, which all exhibit near transform-limited performance with about 100 fs pulse duration. The complete and unconditional absence of Q-switching side bands verifies the small saturation fluence of these devices. [source] Structural 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] High-energy femtosecond fiber lasers based on pulse propagation at normal dispersionLASER & PHOTONICS REVIEWS, Issue 1-2 2008F.W. Wise Abstract The generation and stable propagation of ultrashort optical pulses tend to be limited by accumulation of excessive nonlinear phase shifts. The limitations are particularly challenging in fiber-based devices, and as a result, short-pulse fiber lasers have lagged behind bulk solid-state lasers in performance. This article will review several new modes of pulse formation and propagation in fiber lasers. These modes exist with large normal cavity dispersion, and so are qualitatively distinct from the soliton-like processes that have been exploited effectively in modern femtosecond lasers but which are also quite limiting. Self-similar evolution can stabilize high-energy pulses in fiber lasers, and this leads to order-of-magnitude increases in performance: fiber lasers that generate 10 nJ pulses of 100 fs duration are now possible. Pulse-shaping based on spectral filtering of a phase-modulated pulse yields similar performance, from lasers that have no intracavity dispersion control. These new modes feature highly-chirped pulses in the laser cavity, and a theoretical framework offers the possibility of unifying our view of normal-dispersion femtosecond lasers. Instruments based on these new pulse-shaping mechanisms offer performance that is comparable to that of solid-state lasers but with the major practical advantages of fiber. [source] Laser diodes semicircular side-pumped laser rod with a round-sharped outputLASER PHYSICS LETTERS, Issue 7 2006Y. X. Guo Abstract In order to keep the symmetric of the pump geometry and obtain a low-level, high quality laser output, the temperature of the side-pumped laser rod is more often be controlled by a water cooling system than a conduction cooling system in the diode-pumped solid-state lasers. But the use of the water cooling system increases the volume and decreases the mobility. To solve the confliction between the beam quality and the mobility of the laser system, a novel, compact and all-solid design of the pump structure is applied to the side-pumped laser system. The Nd:YAG rod is pumped by semicircular mounted LD arrays inthe pump module, and two pump modules are working together to compensate each other. Numerical calculation and experiment are performed, the output laser has a round-sharped beam with a beam waist of 5 mm and a divergence angle less than 7 mrad, and a maxim output pulse energy of 75.8 mJ is obtained under the working frequency of 20Hz, the slope efficiency is 35.8%. (© 2006 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Double-resonance grating mirror for polarization control in solid-state lasersLASER PHYSICS LETTERS, Issue 4 2006M. A. Ahmed Abstract The spectral width of the polarizing effect of a coupling grating on a standard quarter-wave multilayer laser mirror can be increased by applying dual-duty-cycle gratings. As an example this is discussed considering the requirements to polarize a Yb:YAG thin-disk laser. By applying dual-duty-cycle gratings the spectral tolerance can be widened by a factor of two as compared to single-duty-cycle designs and at the same time achieve a high reflectivity and low losses for the oscillating polarized laser mode. The calculations of the structures were carried out with the help of an exact modelling code based on the modal method. The code simulates the interaction of a plane electromagnetic wave with the corrugated multilayer structure to compute amplitude and power of all reflected and transmitted diffraction waves. (© 2006 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Lu2O3:Yb3+ ceramics , a novel gain material for high-power solid-state lasersPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2005K. Takaichi Abstract We have developed Yb3+:Lu2O3 ceramics with nanocrystalline technology and a vacuum sintering method. A laser diode end-pumped efficient Yb3+:Lu2O3 ceramic laser was demonstrated. A 0.7 W cw output power was obtained with the slope efficiency of ,36% at 1035 nm wavelength, and 0.95 W with the slope efficiency of ,53% at 1079 nm. We classify the Lu2O3:Yb3+ ceramics as gain medium for high-power solid-state lasers (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] High speed laser processing for monolithical series connection of silicon thin-film modulesPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 3 2008Stefan Haas Abstract A detailed analysis of the monolithical series connection of silicon thin-film modules with metal back contact fabricated by high-speed laser ablation will be presented. In this study, optically pumped solid-state lasers with wavelengths of 1064,nm and 532,nm were used for the patterning process. The influence of various laser parameters on the performance of amorphous and microcrystalline silicon modules will be discussed. In particular, the line-scribing parameters for a TCO and Ag back contact system was analyzed in detail, since it is the most critical patterning step. A detailed description of the back contact ablation process will be presented and a criterion for flakeless patterning was defined. Finally the influence of the back contact patterning on the electrical behavior of silicon single junction cells was studied. The dark current density versus back-contact patterning line length was analyzed by means of a developed SPICE (simulation program with integrated circuit emphasis) simulation model. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||||||||