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1.
We investigate the threshold conditions for coherent soft x-ray generation using a compact hybrid (neodymium-doped glass-sapphire titanate) laser with an output energy of several hundred millijoules. Collisional excitation of molybdenum ions in a longitudinal-pumping scheme was used for x-ray (λ=18.9 nm) generation. The generated radiation exhibited a low divergence and a strong dependence on the delay between picosecond and femtosecond pumping radiations. 相似文献
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Gunnar Blume Christian Kaspari David Feise Alexander Sahm Bernd Sumpf Bernd Eppich Katrin Paschke 《Optical Review》2012,19(6):395-399
Flying-spot displays require light sources in the red, green and blue with a high optical output power and nearly diffraction limited beams. In this paper we present experimental results of red-emitting, AlGaInP based, tapered diode lasers and their integration into diode laser modules. The laser modules emit a collimated, almost diffraction limited beam with an optical output power as high as 1W at a wavelength close to 635 nm. The tapered laser chips were designed with emphasis on achieving a good beam quality in vertical and lateral directions of a collimated beam. To test the suitability for flying-spot display applications, we performed fiber coupling experiments with a low mode number optical fiber with an etendue as low as 6 × 10?6 mm2 sr. A maximum transmission of 70% of the launched power behind the uncoated fiber as well as a usable power in excess of 580mW were measured. 相似文献
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The electronic structure and the soft x-ray spectra of niobium and molybdenum have been calculated. The obtained agreement between the theoretical and experimental spectra made it possible to interpret the MV and NII,III emission bands of niobium and molybdenum. The x-ray emission bands from different series can be used to judge the wave functions of valence band electrons and thus to evaluate the accuracy of the band-structure calculation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 103–106, August, 1973. 相似文献
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14.77 MeV neutron-induced nuclear reaction cross sections for zinc,yttrium, and molybdenum targets 下载免费PDF全文
T.S. Ganesapandy G.T. Bholane S.H. Patil S.S. Dahiwale V.N. Bhoraskar S.D. Dhole 《中国物理C(英文版)》2023,47(3):034002-034002-20
The cross sections for neutron-induced nuclear reactions on natural zinc, yttrium, and molybdenum targets were measured at a neutron energy of 14.77 ± 0.17 MeV using the activation technique, offline gamma-ray spectrometry, and a detailed covariance analysis. The uncertainty in the statistical model calculations of cross sections for the (n, 2n), (n, p), (n, α), and (n, γ) reactions with natural zinc, yttrium, and molybdenum at neutron energies from 13 to 17 MeV was calculated using the TALYS-1.96 nuclear code. The measured cross sections of the present study were compared with the experimental cross sections reported in the EXFOR database, the cross sections were calculated with the TALYS-1.96 and EMPIRE-3.2.3 nuclear codes and the evaluated nuclear data from the TENDL-2019, JENDL-5, and ENDF/B-VIII.0 libraries. 相似文献
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The demonstration of a 69.8?nm laser on 3p 3P2 - 3s 1P1 (J=2-1) transition of Ne-like Ar pumped by capillary discharge is reported in this Letter. A main current of 12?kA with rise time of 43?ns was chosen to generate the plasma in a 35?cm long capillary filling with pressure of Ar as low as 11?Pa, resulting in a gain coefficient of 0.34?cm(-1) and gain-length product of 11 at 69.8?nm. Also observed is a weak laser on 3p 3D2 - 3s 3P1 (J=2-1) transition of Ne-like Ar at 72.6?nm in the same condition. In addition, multiwavelength lasing at 46.9, 69.8, and 72.6?nm was simultaneously realized in a capillary discharge plasma column, conditioning the pressure of Ar to 13?Pa. 相似文献
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Theoretical research on enhancement of gain for Ni-like Ag 13.9nm x-ray laser using a new two-layer target 下载免费PDF全文
For experiments such as on Ni-like Ag x-ray laser, driven by 1\omega
laser, the gain region is only several~nm depth near the target
surface, this paper proposes a new two-layer target, in which a thin
layer (several nm depth) of silver is plated on the surface of some
other materials. Furthermore, the Ni-like Ag 13.9~nm x-ray laser
produced by three new kinds of two-layer target with CH, Al and Ge as
foundation, was theoretically studied. 相似文献
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Larotonda MA Wang Y Berrill M Luther BM Rocca JJ Shakya MM Gilbertson S Chang Z 《Optics letters》2006,31(20):3043-3045
We have measured the pulse duration of gain-saturated 13.9 nm Ni-like Ag and 13.2 nm Ni-like Cd transient collisional lasers excited by grazing-incidence-pumping for several pumping conditions. High-resolution streak-camera measurements yielded FWHM pulse durations close to 5 ps for both lasers under optimum pumping conditions. The very high brightness and short pulse duration of these new high repetition tabletop soft x-ray lasers make them an attractive source for dynamic applications. 相似文献
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The K absorption spectra of zirconium, molybdenum and selenium in ZrSe2 and MoSe2 have been recorded photographically using a Cauchois type bent crystal (mica) spectrograph. The absorption edge shifts are
used along with the data for NbSe2 (Bhide and Bahl 1971J. Phys. Chem. Solids
32 1001) to propose bond schemes for these compounds. 相似文献
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Nguyen Ngoc Ha 《Optics and Spectroscopy》2013,115(2):233-240
In this work, we calculate band structures, the density of state and chemical bonding of the metallic niobium (Nb) and its mono-oxide (NbO) crystals in their solid states using the Density Functional Theory and X-ray Absorption Near Edge Spectroscopy. The electronic properties of Nb and NbO are investigated using the Finite Difference Method. These theoretical results are found in good agreement with the most recent experimental data. Our calculations reveal that the NbO crystal behaves like a superconductor. 相似文献
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V.V. Nemoshkalenko V.P. Krivitskii A.P. Nesenjuk L.I. Nikolajev A.P. Shpak 《Journal of Physics and Chemistry of Solids》1975,36(4):277-281
The L- and M-emission spectra of Zr, Mb and Mo carbides and nitrides have been studied. The spectra were excited by primary techniques, it is concluded that the valence bands of these carbides and nitrides consist of two sub-bands: a sub-band of states which participate in covalent bonds and a sub-band of states which share in the formation of metallic bonding and account for the metallic properties of these phases. 相似文献
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Dielectric properties and substitution preference of yttrium doped barium zirconium titanate ceramics 总被引:1,自引:0,他引:1
The dielectric properties of Ba(Zr0.25Ti0.75)O3+xY 2O3 ceramics are investigated. We believe that, integrating with the lattice parameters, there is an alternation of substitution preference of yttrium ions for the host cations in perovskite lattice that is responsible for the Curie point. The Tc rises with the increase of Y 3+ doping when the doping content is less than 0.05 at%, owing to the replacement of Y 3+ ions for Ba2+ ions at the A-site; when the Y 3+ content is more than 0.05 at%, Y 3+ ions tend to occupy the B-site in perovskite lattice, causing a drop of Tc. Owing to the modifications of Y 3+ doping, the loss tangent of BZT ceramics is depressed remarkably, making it a superior candidate to replace widely used lead-contained ceramics. 相似文献
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Dunn J Li Y Osterheld AL Nilsen J Hunter JR Shlyaptsev VN 《Physical review letters》2000,84(21):4834-4837
We have demonstrated small signal gain saturation on several transient-gain Ni-like ion x-ray lasers by using a high-power, chirped-pulse amplification, tabletop laser. These results have been achieved at wavelengths from 139-203 A using a total of 5-7 J energy in a traveling-wave excitation scheme. Strong amplification is also observed for Ni-like Sn at 119 A. Gain of 62 cm(-1) and gL product of 18 are determined on the 4d-->4p transition for Ni-like Pd at 147 A with an output energy of 12 &mgr;J. A systematic evaluation of the laser driver parameters yields optimum beam divergence and small deflection angles of 2-5 mrads, in good agreement with simulations. 相似文献
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Shao-Chi Lin Sheng-Bai Zhu Qi-Hong Lou Qi-Sheng He 《Journal of Quantitative Spectroscopy & Radiative Transfer》1984,31(6):499-515
A new method is described for determining the small-signal gain and non-saturable absorption coefficients over the same spectral region for high-power lasers. Preliminary tests of this method on the discharge-pumped XeCl excimer laser have yielded B2σ→X2σ gain coefficients which are comparable to those observed in other experiments under similar excitation conditions. However, the absorption coefficient is found to be a high and nearly constant fraction (~) of the gain. This result suggests that all of the absorption processes are due to excited species, including XeCl B2σ. 相似文献
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Cheng Wang-Yau Chen Yi-Shi Cheng Chun-Yen Shy Jow-Tsong Lin Tyson 《Optical and Quantum Electronics》2000,32(3):299-311
In this paper we report our investigations on the frequency stabilization and frequency measurements of 543 nm HeNe laser. It contains following four different works. (1) Using a metal laser tube we have built an iodine-stabilized 543 nm HeNe laser by the Frequency-Modulation (FM) spectroscopy. The signal-to-noise ratio of the hyperfine spectrum reached 2 × 10–12 at 1 s sampling time. (2) We have built a compact iodine-stabilized 543 nm HeNe laser system using the third-harmonic locking technique. Stability better than 1 × 10–12 for sampling time >1 s is obtained. We also suggest the b10 line for the future recommendation. (3) We constructed the Lamb-dip stabilized He-20Ne and He-22Ne lasers and measured their frequency stability, reproducibility, and absolute frequencies. The results suggest that the Lamb-dip stabilized lasers are appropriate for secondary wavelength standards. We have also deduced the isotope shift of Ne atom at 543 nm. (4) We have developed two two-mode stabilized 543 nm HeNe lasers using the bang-bang control method. The Allan variance is 1 × 10–11 at 1 s sampling time. 相似文献
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We report efficient cw laser operation of laser diode pumped Pr(3+)-doped LiYF4 crystals in the visible spectral region. Using two InGaN laser diodes emitting at λ(P)=443.9?nm with maximum output power of 1?W each and a 2.9-mm-long crystal with a doping concentration of 0.5%, output powers of 938?mW, 418?mW, 384?mW, and 773?mW were achieved for the laser wavelengths 639.5?nm, 607.2?nm, 545.9?nm, and 522.6?nm, respectively. The maximum absorbed pump powers were approximately 1.5?W, resulting in slope efficiencies of 63.6%, 32.0%, 52.1%, and 61.5%, as well as electro-optical efficiencies of 9.4%, 4.2%, 3.8%, and 7.7%, respectively. Within these experiments, laser diode-pumped laser action at 545.9?nm was demonstrated for what is believed to be the first time. 相似文献
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Demonstration of coherent addition of multiple gratings for high-energy chirped-pulse-amplified lasers 总被引:1,自引:0,他引:1
Petawatt solid-state lasers require meter-sized gratings to reach multiple-kilojoule energy levels without laser-induced damage. As an alternative to large single gratings, we demonstrate that smaller, coherently added (tiled) gratings can be used for subpicosecond-pulse compression. A Fourier-transform-limited, 650-fs chirped-pulse-amplified laser pulse is maintained by replacing a single compression grating with a tiled-grating assembly. Grating tiling provides a means to scale the energy and irradiance of short-pulse lasers. 相似文献