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51.
Theoretical and experimental investigations of quasi-continuous wave diode array side-pumped Yb'YAG slab laser
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An analytical model of quasi-continuous wave (quasi-CW) diode array side-pumped slab laser for Yb:YAG oscillator in long-pulse free-running has been developed based on the CW model. In this model we first introduce a new parameter, pump pulse width, and make the model available for use in the quasi-CW model. We also give an analytical equation of laser delay time to calculate the laser pulse width. A detailed model is also presented for a new structure laser design, taking account of the geometry of Yb:YAG slab. A quasi-CW diode array side-pumped Yb:YAG slab laser is investigated theoretically and experimentally. Experiments yield a quasi-CW output energy up to 20.36 mJ with the laser pulse width of 654.55 μs at 1049 nm when the diode arrays operate at 25 Hz and 1 ms pulse width. The crystal dimensions are 3 mm×8 mm×1 mm and the doping density is 10 at.%. The experimental results are in good agreement with the predictions of the theoretical model. 相似文献
52.
Movement dynamics analysis for an optical pickup head lens actuator in a digital versatile disc system 总被引:1,自引:0,他引:1
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With the rapid development of CD/DVD(compact disc/digital versatile disc)technology,the disc rotation speed and the information density have increased greatly to fulfil the demand of high informatiopn bit rate transfer,As one of the most important elements in a DVD pickup head,objective lens actuators are required to provide a more precise means to accurately follow the disc deviation.The design of the lens actuator becomes all the more important and critical.In order to give complete suggestion to the design of the lens actuator,we put forward the movement differnetial equations as a new theoretical means to analyse the characteristics of the lens actuator reliably and rigorously.Based on the theoretical analyses,many important and effective methods are propsed.A typical experiment verifies that the performance of our lens actuator head,which adopts these methods,can satisfy the high speed and high density requirement of DVD systems. 相似文献
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基于衍射理论 ,采用更接近光盘实际情况的椭圆型信息符模型并利用光盘的线性叠加原理得到光盘衍射模型的解析表达式 ,对三种主流盘片的盘片倾斜对循迹系统产生的影响进行定量的计算与分析。采用差动相位方式循轨的DVD ROM盘片随径向倾斜的偏移系数为 0 .0 6 μm/(°)。采用推挽方式循轨的DVD RAM盘片循轨误差随径向倾斜的偏移系数为 0 .15 μm/(°)。在相同的盘片参量情况下 ,差动相位检测方法获得循迹误差比推挽方法受盘片径向倾斜的影响更小 ,在读取过程中差动相位检测方法可以获得更好的伺服精度。分析了DVD RAM盘片预刻槽深度与循规误差信号受径向倾斜影响偏移量的关系。实验结果较好的验证了计算和结论。 相似文献
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激光二极管抽运的被动调QNd3+:YAG微晶片激光器及其稳定性 总被引:8,自引:0,他引:8
从理论和实验两个方面研究了连续激光二极管抽运的Cr~(4+):YAG被动调QNd~(3+):YAG微晶片激光器。考虑Cr~(4+):YAG饱和吸收体激发态吸收,推导了连续抽运的被动调Q微晶片激光器的速率方程,分析了微晶片参量对调Q脉冲半峰全宽和峰值功率的影响;提出了实现稳定脉冲输出的微晶片激光器设计原则。在饱和吸收体初始透过率较低(T_0≈40%)的情况下,获得了脉冲峰值功率不稳定性小于±0.7%、脉冲宽度不稳定性小于±1.0%、峰值功率高达千瓦量级的高重复频率激光输出。 相似文献
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