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991.
Laser performance of 1064 nm domestic Nd:YAG ceramic lasers for 885 nm direct pumping and 808 nm traditional pumping are compared. Higher slope efficiency of 34% and maximum output power of 16.5 W are obtained for the 885nm pump with a 6ram length 1 at.% Nd:YAG ceramic. The advantages for 885nm direct pumping are discussed in detail. This pumping scheme for highly doping a Nd:YAG ceramic laser is considered as an available way to generate high power and good beam quality simultaneously. 相似文献
992.
Effect of Different Substrate Temperature on Phosphorus-Doped ZnO Thin Films Prepared by PLD on Sapphire Substrates 下载免费PDF全文
Phosphorus-doped ZnO (ZnO:P) thin films are deposited on a c-plane sapphire in oxygen at 350℃, 450℃, 550℃ and 650℃, respectively, by pulsed laser deposition (PLD), then all the ZnO:P samples are annealed at 650℃ in oxygen with a pressure of 1 × 10^5 Pa. X-ray diffraction measurements indicate that the crystalline quality of the ZnO:P thin films is improved with the increasing substrate temperature from 350℃ to 550℃. With a further increase of the deposition temperature, the crystalline quality of the ZnO:P sample is degraded. The measurements of low-temperature photoluminescence spectra demonstrate that the samples deposited at the substrate temperatures of 350℃ and 450℃ show a strong acceptor-bound exciton (A^0X) emission. The electrical properties of ZnO:P films strongly depend on the deposition temperature. The ZnO:P samples deposited at 350℃ and 450℃ exhibit p-type conductivity. The p-type ZnO:P film deposited at 450℃ shows a resistivity of 1.846Ω·cm and a relatively high hole concentration of 5.100 × 10^17 cm^-3 at room temperature. 相似文献
993.
Intrinsic Bistability and Critical Slowing in Tm^3+/Yb^3+ Codoped Laser Crystal with the Photon Avalanche Mechanism 下载免费PDF全文
We present theoretically a novel intrinsic optical bistability (IOB) in the Tm^3+ /Yb^3+ codoped system with a photon avalanche mechanism. Numerical simulations based on the rate equation model demonstrate distinct 10B hysteresis and critical slowing dynamics around the avalanche thresholds. Such an 10B characteristic in Tm^3+ /Yb^3+ eodoped crystal has potential applications in solid-state bistable optical displays and luminescence switchers in visible-infrared spectra. 相似文献
994.
In the comparison of damage modifications, absorption measurement and energy dispersive x-ray analysis, the effect of vacuum on the laser-induced damage of anti-reflection coatings is analyzed. It is found that vacuum decreases the laser-induced damage threshold of the films. The low laser-induced damage threshold in vacuum environments as opposed to air environments is attributed to water absorption and the formation of the O/Si, O/Zr sub-stoichiometry in the course of laser irradiation. 相似文献
995.
利用Utev S.和Peligrad M.不等式,得到了(p)-混合随机变量序列Hájeck-Rènyi不等式、三级数定理和Chung型强大数律,改进了甘师信与吴群英等人的结论,达到了与独立时一致的结果. 相似文献
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999.
The trajectory-density method operators. We propose a new of a quantum system is developed by scheme of approximation from two using local Koopman and Frobenius-Perron sets of trajectory-density mixed equations. By examining the local generation and termination of trajectories, we show how they can be adopted to the propagation of negative values of the Wigner function even if it starts off positive everywhere. 相似文献
1000.