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The beam quality of a single-rod Nd: YAG laser with wavelength of 1.06 m was improved almost up to the diffraction limit by using a phase-conjugating mirror (PCM) based on stimulated Brillouin scattering (SBS) with acetone as the SBS medium. The new start cavity, which is the concave-convex cavity operating near the limit of stability in the g diagram, and the phase conjugation cavity of the SBS oscillator were designed. The thermal lens of the material with focal lengths of less than 140 m at pump powers of 60 J was compensated by the PCM. The laser is Q-switched by the nonlinear reflectivity of the PCM and the system works with an average repetition rate of about 5 kHz and single Q-switch pulse showed a width of 10 ns. It is demonstrated that if the start cavity is fit for SBS and the SBS phase conjugation mirror can be optimized, the beam quality of solid laser can be surely enhanced because of this technology of nonlinear optics. 相似文献
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Yusuke Arai Tetsuji Yano Shuichi Shibata 《Journal of Sol-Gel Science and Technology》2004,32(1-3):189-194
Microspheres of refractive index of nD > 2.0 have been investigated. The organic-inorganic hybrid microspheres of nD = 1.72 were prepared by the vibrating orifice technique using titanium-tetra-n-butoxide (TTBu) and diphenyldimethoxysilane (DPhDMS). For lasing demonstration, Eu3+-doped microspheres were prepared using europium (III) thenoyltrifluoroacetonate [Eu(TTFA)3] as the dopant. The particles have good spherical shape, smooth surface and high optical transparency. The diameters of the particles could be controlled to within 0.1 m. Subsequent heating of the microspheres at 550°C under oxygen atmosphere resulted in an increase in the refractive index up to nD = 2.6 with retention of the spherical shape. Resonant emission was confirmed from Eu3 +-doped microspheres after heating at 400–550°C, by pumping with the 514.5 nm line of a CW- Ar+laser. 相似文献
148.
Solutions are obtained for the stress state problem for an elastic space with an internal toroidalshaped cavity that can be expanded in a trigonometric series in the angle in cylindrical coordinates. Displacements and stresses are specified on the boundary. An analytic solution of the problem is found using generalized analytic functions. Stresses and displacements of points in the elastic space are calculated. 相似文献
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Two Solutions to Diluted p-Spin Models and XORSAT Problems 总被引:1,自引:0,他引:1
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