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Laser Operation (laser + operation)

Distribution by Scientific Domains
Physics and Astronomy87%

Selected Abstracts

Structural Changes in the BODIPY Dye PM567 Enhancing the Laser Action in Liquid and Solid Media,

ADVANCED FUNCTIONAL MATERIALS, Issue 16 2007
I. 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]

Crystal growth, optical properties, and continuous-wave laser operation of Nd3+ -doped CaNb2O6 crystal

LASER PHYSICS LETTERS, Issue 10 2009
Y. Cheng
Abstract Laser crystal Nd:CaNb2O6 with excellent quality has been grown by Czochralski technique. The effective segregation coefficient of Nd3+ was studied by X-ray fluorescence method. The polarized absorption spectra and the fluorescence spectra of Nd:CaNb2O6 were measured at room temperature. The peak absorption cross section was calculated to be 6.202×10,20 cm2with a broad FWHM of 7 nm at 808 nm for E , a light polarization. The emission cross section at 1062 nm is 9.87 × 10,20 cm2. We report what we believe to be the first demonstration of the continuous-wave Nd:CaNb2O6 laser operation under diode pumping. Output power of 1.86 W at 1062 nm was obtained with a slope efficiency of 19% in the CW regime. (© 2009 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Continuous-wave laser operation at 1.33 ,m of Nd:CNGG and Nd:CLNGG crystals

LASER PHYSICS LETTERS, Issue 3 2008
Z.B. Shi
Abstract With a laser-diode (LD) as the pump source, continuous-wave (cw) laser performance at 1.33 ,m of Nd:CNGG and Nd:CLNGG crystals was demonstrated for the first time. The maximum power of 158 mW and 141 mW from Nd:CNGG and Nd:CLNGG lasers were obtained with the corresponding optical conversion efficiencies of 1.3% and 1.5%, and slope efficiencies of 2.0% and 2.9%, respectively. The difference between the laser performance of Nd:CNGG and Nd:CLNGG crystals was also discussed. (© 2008 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Multimode fiber lasers based on Bragg gratings and double-clad Yb-doped fibers

LASER PHYSICS LETTERS, Issue 9 2004
A. S. Kurkov
Abstract We have realized a set of multimode lasers based on a double-clad Yb-doped fiber and Bragg gratings written on a graded-index multimode fiber. Efficient laser operation in the spectral range of 1.03-1.09 ,m has been observed. Spectral characteristics of the laser emission have been investigated. (© 2004 by ASTRO, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Single mode Tm and Tm,Ho:LuAG lasers for LIDAR applications

LASER PHYSICS LETTERS, Issue 6 2004
K. Scholle
Abstract In this paper we report on diode pumped single mode Tm:LuAG and Tm,Ho:LuAG lasers which are developed as master oscillators for an airborne LIDAR system. Using a new fourfold pump setup 51 mW of output power with a Tm(10%):LuAG laser were reached at room temperature. The Tm(10%),Ho(0.4%):LuAG laser proved to be more temperature sensitive than the Tm laser. 18 mW and 30 mW of single mode laser output could be achieved at room temperature and 0 °C, respectively. In multi mode laser operation 130 mW output power at room temperature (slope efficiency 36%) were achieved. (© 2004 by ASTRO Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Long-wavelength (, , 1.3 µm) InGaAlAs,InP vertical-cavity surface-emitting lasers for applications in optical communication and sensing

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 14 2006
Markus-Christian Amann
Abstract In this paper we present an overview of the properties and applications of long-wavelength vertical-cavity surface-emitting lasers (VCSELs) based on the InGaAlAs,InP material system. With respect to significant temperature sensitivity of active material gain as well as insufficient thermal conductivity of InP-based epitaxial compound layers, the effective thermal heat management appears as a major issue for application suitable device performance. In this context, the incorporation of a buried tunnel junction (BTJ) in connection with improved heat sinking resembles a breakthrough for long-wavelength VCSELs. With the utilization of n-type spreading layers and consequently ultralow series resistances, BTJ-VCSELs exhibit sharply reduced excess heat generation. Furthermore, the BTJ-approach enables self-aligned optical and current confinement. A hybrid dielectric stack with Au-coating yields an improved thermal heatsinking. The current status of BTJ-VCSELs encompasses a number of superior performance values. At 1.55 µm wavelength, this includes room temperature single- and multimode continuous wave (cw) output powers of more than 3 mW and 10 mW, respectively, laser operation for heat sink temperatures well exceeding 100 °C, and optical data transmission rates up to 10 Gbit/s. The versatility of compound layer composition enables arbitrary emission wavelengths within a broad range of 1.3 and 2 µm. With respect to sensing applications, BTJ-VCSELs appear as ideal components for optical detection of infrared active gases. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Continuous-wave and tunable laser operation of Tm:LuVO4 near 1.9 µm under Ti:sapphire and diode laser pumping

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 4 2006
X. Mateos
Abstract We demonstrate for the first time to our knowledge laser oscillation of Tm:LuVO4 at room temperature with both Ti:sapphire and diode laser pumping, and tunable operation from 1839 to 1952 nm. Spectroscopic studies indicate higher gain cross section for the ,-polarization as observed in the laser experiments. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]