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41.
Controllable photoinduced optical attenuation in a single-mode optical fiber by irradiation of a femtosecond pulse laser 总被引:1,自引:0,他引:1
Novel optical attenuation fibers were fabricated by the irradiation of a focused infrared femtosecond pulsed laser onto the core of a silica glass single-mode optical fiber. Optical attenuation at a wavelength of 1.55 microm proportionally increased with increasing numbers of irradiation points and was controllable under laser irradiation conditions. The single-mode property of the waveguide and the mode-field diameter of the optical fiber were maintained after irradiation of the femtosecond laser. It is suggested that the attenuation results from optical scattering at photoinduced spots formed inside the fiber core. 相似文献
42.
Fourier transform emission spectra of CoCl were obtained with a tube furnace-DC discharge source in the 450-500 nm spectral region. In addition to observing two different band systems, which were assigned as [20.7] and [21.3] by Adam et al. [J. Mol. Spectrosc. 212 (2002) 111], we obtained data for additional sub-bands and vibrational levels. In contrast to the previous work, intense Q branches are seen in the [21.3]- bands which indicate that these bands are likely ΔΛ≠0 transitions. The equilibrium rotational constant Be for the ground state is 0.1801104(28) cm−1, the equilibrium bond length is 2.065122(16) Å and ΔG1/2 is 430.418(5) cm−1. 相似文献
43.
Shinobu Onoda Toshio Hirao Takeshi Ohshima Hisayoshi Itoh 《Radiation Physics and Chemistry》2009,78(12):1116-1119
The effect of radial ion-track distribution on the transient current in semiconductors caused by a high-energy heavy ion strike was studied. Reasonable agreement was observed in experimental and calculated transient currents for ion energies ranging from several to several hundred MeV when the radius of the ion track used in the numerical simulations was shorter or equivalent to that of the penumbra radius. 相似文献
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This paper clarifies why long-range corrected (LC) density functional theory gives orbital energies quantitatively. First, the highest occupied molecular orbital and the lowest unoccupied molecular orbital energies of typical molecules are compared with the minus vertical ionization potentials (IPs) and electron affinities (EAs), respectively. Consequently, only LC exchange functionals are found to give the orbital energies close to the minus IPs and EAs, while other functionals considerably underestimate them. The reproducibility of orbital energies is hardly affected by the difference in the short-range part of LC functionals. Fractional occupation calculations are then carried out to clarify the reason for the accurate orbital energies of LC functionals. As a result, only LC functionals are found to keep the orbital energies almost constant for fractional occupied orbitals. The direct orbital energy dependence on the fractional occupation is expressed by the exchange self-interaction (SI) energy through the potential derivative of the exchange functional plus the Coulomb SI energy. On the basis of this, the exchange SI energies through the potential derivatives are compared with the minus Coulomb SI energy. Consequently, these are revealed to be cancelled out only by LC functionals except for H, He, and Ne atoms. 相似文献
47.
Shimizu M Sakakura M Kanehira S Nishi M Shimotsuma Y Hirao K Miura K 《Optics letters》2011,36(11):2161-2163
We report on the formation mechanism of element distribution in glass under high-repetition-rate femtosecond laser irradiation. We simultaneously focused two beams of femtosecond laser pulses inside a glass and confirmed the formation of characteristically shaped element distributions. The results of the numerical simulation in which we considered concentration- and temperature-gradient-driven diffusions were in excellent qualitative agreement with the experimental results, indicating that the main driving force is the sharp temperature gradient. Since the composition of a glass affects its refractive index, absorption, and luminescence property, the results in this study provide a framework to fabricate a functional optical device such as optical circuits with a high-repetition-rate femtosecond laser. 相似文献
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Guizhou Yue Kaining Lei Hajime Hirao Jianrong Zhou 《Angewandte Chemie (International ed. in English)》2015,54(22):6531-6535
Asymmetric reductive Heck reaction of aryl halides is realized in high stereoselectivity. Hydrogen‐bond donors, trialkylammonium salts in a glycol solvent, were used to promote halide dissociation from neutral arylpalladium complexes to access cationic, stereoselective pathways. 相似文献