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61.
Investigation of Brillouin effects in small-core holey optical fiber: lasing and scattering 总被引:6,自引:0,他引:6
We demonstrate for what is believed to be the first time a Brillouin laser based on a holey fiber (HF). Using a simple Fabry-Perot resonator scheme containing a 73.5-m-long highly nonlinear HF with an effective area of 2.85 microm(2) , we obtain a threshold of 125 mW and a slope efficiency of ~70% . Stimulated and spontaneous Brillouin scattering effects are investigated in the HF, and we show that the high lasing threshold is due mainly to reduction of the effective gain coefficient caused by structural nonuniformity along the fiber length. 相似文献
62.
Greater than 20%-efficient frequency doubling of 1532-nm nanosecond pulses in quasi-phase-matched germanosilicate optical fibers 总被引:2,自引:0,他引:2
Pruneri V Bonfrate G Kazansky PG Richardson DJ Broderick NG de Sandro JP Simonneau C Vidakovic P Levenson JA 《Optics letters》1999,24(4):208-210
We fabricated second-order nonlinear gratings in D-shaped germanosilicate fibers, using thermal poling and periodic electrodes defined by standard photolithography. These gratings, which are up to 75 mm long, were used for efficient quasi-phase-matched frequency doubling of 1.532-mum nanosecond pulses from a high-power erbium-doped fiber amplifier. Average second-harmonic powers as high as 6.8 mW and peak powers greater than 1.2 kW at 766 nm were generated, with average and peak conversion efficiencies as high as 21% and 30%, respectively. 相似文献
63.
M.A.H. Smith G.A. Harvey G.L. Pellett A. Goldman D.J. Richardson 《Journal of Molecular Spectroscopy》1984,105(1):105-112
N2-broadened halfwidths have been measured for 51 absorption lines belonging to the ν3 fundamental band of hydrogen cyanide (1H12C14N) near 3311 cm?1. The data were recorded at room temperature using a Fourier transform spectrometer with a nominal resolution of 0.06 cm?1. A nonlinear least-squares spectral-fitting procedure was used to obtain both line intensities and collision-broadened halfwidths from scans recorded at several different pressures. The N2-broadened halfwidths, determined for all lines with J ≤ 25 in both the P and R branches of the band, show the expected distribution with J for broadening by a nonpolar gas. The halfwidth values range from approximately 0.17 cm?1 atm?1 near the band center to 0.11 cm?1 atm?1 for high-J lines. The band intensity for the ν3 fundamental derived from these measurements is 236.2 ± 9.5 cm?2 atm?1 at 296 K, and empirical coefficients for the vibration-rotation interaction F-factor were also determined. 相似文献
64.
A.B. Gardner S. Howard T.C. Waddington R.M. Richardson J. Tomkinson 《Chemical physics》1981,57(3):453-460
Incoherent quasi-elastic neutron scattering has been used to study the reorientational motions of the cyclopentadienyl rings in ferrocene, nickelocene and ruthenocene. The results for ferrocene show that the activation energy for ring rotation drops above the 164 K phase transition to 4.4 ± 0.5 kJ mol?1 (which is approximately half its low temperature value) but the rings still appear to jump between only five orientations on the observable time scale. At room temperature, the rings in nickelocene appear to behave the same as in ferrocene but in ruthenocene they reorientate much less frequently and resemble those in ferrocene below 164 K. 相似文献
65.
R.S. Marjoribanks M.C. Richardson J. Delettrez S. Letzring W. Seka D.M. Villeneuve 《Optics Communications》1982,44(2):113-116
Preliminary experiments using an X-ray streak filter spectrometer employing a Au/CsI bifurcated photocathode to investigate the X-ray history of UV (350 nm) laser produced plasmas are reported. Novel use of the streak spectrometer permits a direct and precise fiducial record of the laser pulse to be made from specularly scattered laser light, in true streak time relative to the X-ray record. Initial data indicates a constant 700 eV temperature during the laser pulse; time-resolved particulars are compared to simulations made by the design code LILAC. 相似文献
66.
Joshi Shrikant V. Park Jin Y. Taylor P. R. Richardson L. S. 《Plasma Chemistry and Plasma Processing》1985,5(2):143-161
Plasma Chemistry and Plasma Processing - A new integral mean diffusivity is proposed for the calculation of the mass transfer rate around a small particle immersed in a thermal plasma gas.... 相似文献
67.
Leonard F. Richardson 《Mathematische Annalen》1979,239(3):229-240
68.
W.?KilianEmail author T.?Plehn P.?Richardson E.?Schmidt 《The European Physical Journal C - Particles and Fields》2005,39(2):229-243
We consider the collider phenomenology of split-supersymmetry models. Despite the challenging nature of the signals in these models the long-lived gluino can be discovered with masses above 2 TeV at the LHC. At a future linear collider we will be able to observe the renormalization group effects from split supersymmetry, using measurements of the neutralino and chargino masses and cross sections.Received: 15 August 2004, Revised: 29 September 2004, Published online: 11 January 2005 相似文献
69.
The NMR spectra of a series of 1,3,5-triazines (1) in which one or more of the substituent groups are fluorinated are described, and the results are discussed in terms of bonding and geometry of the molecules. Remote effects of unsymmetrical substitution are observed in the fluorine-19 and carbon-13 spectra, in some molecules indicating restricted rotation about the bond joining an amino group to a ring carbon. 相似文献
70.
Femtosecond laser direct writing is employed for the fabrication of buried tubular waveguides in bulk poly(methyl methacrylate). A novel technique using selective chemical etching is presented to resolve the two-dimensional refractive-index profile of the fabrication structures. End-to-end coupling in the waveguides reveals a near-field intensity distribution that results from the superimposition of several propagating modes with different azimuthal symmetries. Mode analysis of the tubular waveguides is performed using the finite-difference method, and the possible propagating mode profiles are compared with the experimental data. 相似文献