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41.
提出一种基于高双折射光子晶体光纤与光纤环的超宽带可调谐微波光子滤波器.以多波长光纤激光器作为光源,向高双折射光子晶体光纤内填充温敏液体,通过改变填充温敏液体的温度,高双折射光子晶体光纤可具有不同的双折射,得到不同波长间隔的激光,从而使微波光子滤波器具有不同的自由频谱范围.当温度的变化范围为20~80℃时,仿真测得微波光子滤波器自由频谱的变化范围为2.49~39.9GHz.引入光纤环构建级联型微波光子滤波器,滤波器的主旁瓣抑制比可提高到33.6dB,Q值可达到499,提高了滤波器的频率选择性. 相似文献
42.
We present results of research on the effect of the parameters of an XeCl-laser excitation system patterned after an LC-inverter
on the energy characteristics of the laser. The effect of each of the parameters and their collection is established. We obtained
conditions for matching the parameters of the excitation circuit of an XeCl-laser on satisfaction of which the lasing energy
acquires a maximum value. It is shown that the energy characteristics of the laser are determined by the processes occurring
in the inversion circuit and by the dynamics of the voltage across the interelectrode spacing.
To whom correspondence should be addressed.
Reported at the Second International Scientific and Technical Conference on Quantum Electronics, Minsk, November 23–25, 1998.
Ya. Kupala Grodno State University, 22, Ozheshko Str., Grodno, 230023, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 66, No. 5, pp. 702–707, September–October, 1999. 相似文献
43.
44.
Intra-cavity phase anisotropy causes each laser longitudinal mode to split into two orthogonally polarized frequencies. When the frequency difference generated by small anisotropy is about 40 MHz or less, only one frequency of the splitting mode oscillates while the other is always in lock-in state due to strong mode competition. In that case the longitudinal mode spacing deviates from its original value. And the spacing of two adjacent longitudinal modes shows differential variations depending on direction of cavity length tuning and mode polarization. In this paper, the relationship between spacing variation and small intra-cavity anisotropy is demonstrated experimentally and theoretically. The equivalent fast axis of anisotropy is determined additionally by its correlation with laser intensity tuning of the two orthogonally polarized components. The novel measurement method is successfully tested in several applications. 相似文献
45.
A laser image system for investigating the influence of orifice spacing on twin bubbles formation in shear-thinning fluid was established. The bubbles formation process at two orifices could be directly visualized and real-time recorded through computer by means of He–Ne laser as light source using the beam expanding and light amplification technology. The shape and size of bubbles generating in carboxymethylcellulose (CMC) aqueous solutions were studied experimentally at the orifices spacing 1Do, 2Do and 3Do (Do orifice diameter). The results reveal that the minute bubbles can be imaged clearly and amplified without distortion in the higher concentration solutions, and therefore the shape and size of bubbles are obtained accurately. With the increase of orifice spacing, bubble instantaneous volume in shear-thinning fluid decreases at the radial expansion stage but then increases at vertical elongation period, and the deformation and deviation of bubbles forming goes down due to the reduced interaction of adjacent bubble. 相似文献
46.
A simple genetic algorithm is implemented to perform multi parameter optimization of Raman Fiber Amplifier for 100 channel S band dense wavelength division multiplexed system at 25 GHz interval. A cost effective system using single Raman pump is investigated aiming at maximum average gain. The single counter propagating pump is optimized to frequency of 211.528 THz and 652.93 mW power level with optimum Raman fiber length of 44.064 Km. There is evidence to show that the optimum solution presents a small gain variation (less than 3 dB) over an effective bandwidth covering 197–199.475 THz. The optimized configuration enabled an adequate system performance in terms of acceptable Q-factor (19.52 dB) and BER (1.46 × 10−21). 相似文献
47.
48.
采用电子束光刻、热蒸镀和剥离工艺在室温下制备了多组磁性量子元胞自动机器件功能阵列. 实验研究了曝光剂量和曝光时间对三个不同间距参数磁性量子元胞自动机阵列图案的影响, 发现100 pA电子束束流和0.38 μs曝光时间可获得理想的阵列图案. 对制备的反相器阵列结构进行了磁力显微测试, 结果显示了正确的逻辑功能, 成功实现了不同间距参数功能阵列的实验制备. 此外, 实验还发现纳磁体阵列制备中容易出现缺陷, 模拟结果表明丢失纳磁体缺陷导致了信号传递反相. 相似文献
49.
本文用Multi-Block算法和标准的κ-ε模型计算轴对称自由射流,计算中发现:(1)不同的纵向网格宽度比(疏密度比)会导致不同的扩张速率的计算结果。(2)在相同的网格疏密度比下,由于不同喷管长度L带来的射流上游进口的湍流结构的变化与下游射流扩张速率有清晰的关联。 相似文献
50.
Alan T. Murray 《Annals of Operations Research》2003,123(1-4):143-156
Accessible and efficient service are vital features of well-utilized public transit systems. Modeling approaches to support the evaluation of transit operations for management and planning are essential for continued improvement. A hybrid coverage model is developed in this paper for simultaneously expanding service access and increasing accessibility. This paper discusses the use and integration of this model in a geographic information system environment for strategic planning. Analysis is presented for public transit service in Brisbane, Australia. The structured model provides flexibility in developing viable policies for addressing system improvements and service expansion, all of which are likely to promote increased utilization of public transit. 相似文献