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981.
A. Nakajima Y. Masuda E. Matsuda Y. Ueda H. Sameshima T. Ikenoue 《Applied magnetic resonance》2011,40(4):535-544
The reaction between 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCAM), which is a blood–brain-barrier (BBB)
permeable stable cyclic nitroxide, and ascorbic acid was examined in a low dissolved oxygen-phosphate buffer (low DO-PB, 0.1 mM
DO) under 8% oxygen in a glove bag or in an ordinal dissolved oxygen-phosphate buffer (ordinal DO-PB, 0.3 mM DO) under 21%
oxygen in an open atmosphere with and without diethylenetriaminepentaacetic acid (DTPA). In PB with DTPA, no difference was
observed between the results in the low DO-PB and those in the ordinal DO-PB. In the ordinal DO-PB without DTPA, the rate
constant of the PCAM decrease was half that in the low DO-PB without DTPA. The present results indicate that high DO and coexisting
transition metal ions caused the oxidation of ascorbic acid, which degraded the PCAM reduction. The stable nitroxide-ascorbic
acid system without DTPA was found to be applicable to an in vitro model for the acute hypoxia ischemia. 相似文献
982.
A passively Q-switched 1.06 μm laser with Cr4+:YAG saturable absorber by direct 879 nm diode pumping grown-together composite GdVO4/Nd:GdVO4 crystal to the emitting level was demonstrated in this paper. The characteristics of pulsed laser were investigated by using
two kinds of Cr4+:YAG crystal with the initial transmissivity of 80 and 90%, respectively. When the T
0 = 90% Cr4+:YAG was used, an average output power of 1.59 W was achieved at an incident pump power of 10 W. The pulse width and repetition
rate were 64.5 ns and 170 kHz, respectively. The thermal lens effect of laser crystal was analyzed. 相似文献
983.
A Q-switched high efficient Ho:YAlO3 (Ho:YAP) laser pumped by a diode-pumped Tm:YLF laser at room-temperature is realized. The maximum output energy reaches 1.58
mJ under the repetition frequency of 5 kHz, when the incident pump power is 15.6 W. The pulse width is 22 ns. The wavelength
is 2118 nm when the transmission of output coupler is 30%. The beam quality factor is M
2 ∼ 1.39 measured by the traveling knife-edge method. 相似文献
984.
J.-H. Yuan X.-Z. Sang C.-X. Yu L. Rao Y. Han G.-Y. Zhou S.-G. Li L.-T. Hou 《Applied physics. B, Lasers and optics》2011,105(4):685-688
Using the photonic crystal fiber (PCF) with the zero dispersion wavelength of 848 nm for the fundamental mode, the efficient
anti-Stokes signal generations from 645 to 543 nm are realized by pumping in the normal dispersion region. When the pump average
power increases from 200 to 500 mW, the output power of the anti-Stokes signal increases 8.46 times, the power ratio of the
anti-Stokes signal at 543 nm to the residual pump is calculated as 22.6:1, and the conversion efficiency η in the experiment can be up to 46%. Moreover, good optical beam quality of the anti-Stokes signal can be achieved. 相似文献
985.
X. F. Yang D. Y. Shen T. Zhao H. Chen J. Zhou J. Li H. M. Kou Y. B. Pan 《Laser Physics》2011,21(6):1013-1016
We report on a high power polycrystalline Er:YAG ceramic laser in-band pumped by a cladding-pumped Er, Yb fiber laser wavelength
locked at 1532 nm with a volume Bragg grating. Using 1.0 at % Er3+-doped ceramic as the gain medium and an output coupler of 10% transmission, the laser had a threshold pump power of ∼1.5
W and generated 11 W of continuous-wave output at 1645 nm for 23.3 W of incident pump power at 1532 nm, corresponding to a
slope efficiency with respect to incident pump power of 51%. 相似文献
986.
Diode-pumped Pr<Superscript>3+</Superscript>:YAlO<Subscript>3</Subscript>/LBO violet laser at 374 nm
We report a diode-pumped Pr3+:YAlO3 laser emitting at 747 nm. A power of 232 mW at 747 nm has been achieved in continuous-wave operation with a diode emitting
2 W at 448 nm. Furthermore, intracavity second-harmonic generation in continuous-wave mode has also been demonstrated with
a power of 52 mW at 374 nm by using a LBO nonlinear crystal. The fluctuation of the violet output power was better than 2.3%.
The beam quality M
2 value is 2.2. 相似文献
987.
A simple scheme for a switchable multi-wavelength erbium-doped fiber (EDF) ring laser is investigated by using a single stage
of a Sagnac loop mirror. The multiple lasing outputs are obtained and switched readily by controlling the state of polarization
(SOP). Since the transmission characteristics of the Sagnac loop mirror in terms of peak wavelengths and peak powers strongly
depend on the SOP, the switching performance of the proposed multi-wavelength EDF laser can be effectively obtained. The proposed
multi-wavelength EDF laser has versatile lasing outputs in states of a single-, dual-, triple-, and quadruple-wavelength oscillations.
The multiple outputs are effectively switchable by adjusting the SOP. 相似文献
988.
X. Ni G. V. Naik A. V. Kildishev Y. Barnakov A. Boltasseva V. M. Shalaev 《Applied physics. B, Lasers and optics》2011,103(3):553-558
Spontaneous emission patterns of electric and magnetic dipoles on different metallic surfaces and a hyperbolic metamaterial
(HMM) surface were simulated using the dyadic Green’s function technique. The theoretical approach was verified by experimental
results obtained by measuring angular-dependent emission spectra of europium ions on top of different films. The results show
the modified behavior of electric and magnetic dipoles on metallic and HMM surfaces. The results of numerical calculations
agree well with experimental data. 相似文献
989.
The efficient oscillation of LiF:F2− color center laser pumped by a compact LD-pumped Nd:YVO4 acousto optically Q-switched laser with 30 kHz pulse repetition rate was demonstrated. The broadband oscillation with 75
μJ pulse energy and 37 kW peak power with the slope efficiency 20% was obtained. The average output power as high as 230 mW
was reached. The narrow line tunable from 1.10 to 1.29 μm laser radiation with 10% conversion efficiency in the maximum of
the tuning curve was achieved under pumping with 1.6 W average pump power. 相似文献
990.
We report a diode-pumped Nd:LuVO4 laser emitting at 1076 nm, based on the 4
F
3/2−4
I
11/2 transition, generally used for a 1066 nm emission. A power of 689 mW at 1076 nm has been achieved in continuous-wave (CW)
operation with a fiber-coupled laser diode emitting 17.8 W at 809 nm. Intracavity second-harmonic generation (SHG) in CW mode
has also been demonstrated with a power of 105 mW at 538 nm by using a LiB3O5 (LBO) nonlinear crystal. 相似文献