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51.
应用等效原理,通过引入口面上等效磁流将含腔导电目标电磁散射简化为腔内、外两个等效 问题. 腔内问题分段求解并应用级联法获得口面等效导纳矩阵;腔内外的耦合关系应用近似 边界元方法描述并由此获得口面等效磁流;最后,这一具有混合源的腔体内外一体化散射问 题则应用所提出的广义混合场积分方程方法建立电磁模型,并用多层快速多极子方法实现高 效数值求解. 实例计算结果与测试结果具有很好的一致性.
关键词:
含腔目标
电磁散射
混合场积分方程
数值分析 相似文献
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53.
500.8 nmNd∶YAG青光激光器光学薄膜的设计与制备 总被引:5,自引:2,他引:3
从双波长激光运转及和频的机理出发,对LD泵浦Nd∶YAG,LBO腔内和频500.8 nm〖JP2〗青光激光器所使用的光学薄膜进行了设计和制备.在激光反射镜的设计上,为了达到最佳的和频输出,对膜系要求进行了深入分析.采用对谐振腔一端面反射率固定不变并通过对另一腔镜基频光的透射率进行调谐的方法, 在给出合理初始结构后,利用计算机对膜厚进行了优化.并采用双离子束溅射沉积的方法,通过时间监控膜厚法成功制备出青光激光器所使用的全介质激光反射膜, 在室温下实现946 nm和1064 nm双波长连续运转,并通过Ⅰ类临界相位匹配LBO晶体腔内和频在国内首次实现500.8 nm青色激光连续输出.当泵浦注入功率为1.4 W时和频青光最大输出达20 mW. 相似文献
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Fu-li Li Zhang-qi Yin 《量子光学学报》2006,12(B08):75-75
Two atomic clusters, which have NA and Ns two-level atoms, respectively, are placed in a cavity but separated spatially. There is no direct interaction between the atoms. All the atoms interact with a single-mode of the cavity field. Quantum entanglement between the two atomic clusters is investigated for various initial states of the two atomic clusters and the field. When the cavity field is initially in a Fock state, we find that the time evolution of entanglement quasi-periodically oscillates regardless of the initial states of atoms. The oscillation period increases as the initial photon number increases. When all the atoms in both of the atomic clusters are initially in the excited state, we show that there is no entanglement between the atomic clusters with NA = NB = 1 regardless the initial state of the cavity field. However, when either NA or NB is larger than one, we find that the entanglement always exists even for a strong thermal field. In cases with different initial states of the atomic clusters, we notice that the entanglement becomes stronger as number of the atoms increases. When all the atoms in both of the clusters in the ground state, we also find that the entanglement can be enhanced even by a thermal field. We also notice that a single qubit can be entangled with multi-atoms which are initially in the ground state by the cavity field initially being in vacuum, thermal, coherent, and squeezed states. 相似文献
57.
研究了频率随时间变化的压缩态光场与二能级原子的相互作用,主要讨论了光场频率随时间作正弦调制和脉冲调制两种典型情况下,原子布居数反转随时间的演化特性。当光场频率随时间作正弦调制时,不仅光场频率调制,而且压缩态的压缩系数和压缩相位均对原子布居数反转的崩塌—回复过程有影响。当光场频率随时间作脉冲调制时,在原子布居数反转随时间演化过程中诱导出新的崩塌—回复过程,尤其在脉冲出现的区间内,原子布居数反转表现出持续的小幅快速振荡,这与压缩态的压缩系数无关。 相似文献
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Realization of Greenberg-Horne-Zeilinger (GHZ) and W Entangled States with Multiple Superconducting Quantum-Interference Device Qubits in Cavity QED
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An alternative scheme is proposed for generating the Greenberg-Horne-Zeilinger (GHZ) and W types of the entangled states with multiple superconducting quantum-interference device (SQUID) qubits in a single-mode microwave cavity field. In this scheme, there is no transfer of quantum information between the SQUIDs and the cavity, the cavity is always in the vacuum and thus the requirement on the quality of cavity is greatly loosened. In addition, during the process of the generation of the W entangled state, the present method does not involve a real excitation of intermediate levels. Thus, decoherence due to energy relaxation of intermediate levels is minimized. 相似文献
60.
ZHANG Jialu 《声学学报:英文版》2006,25(3):204-208
It has been a barrier that the place code is far too coarse a mechanism to account for the finest frequency difference limen for place theory of hearing since it was proposed in 19th century. A place correlation model, which takes the energy distribution of a pure tone in neighboring bands of auditory filters into full account, was presented in this paper. The model based on the place theory and some experimental results of the psychophysical tuning curves of hearing can explain the finest difference limen for frequency (about 0.02 or 0.3% at 1000 Hz) easily. Using a standard 1/3 octave filter bank of which the relationship between the frequency of a input pure tone apart from the centre frequency of K-th filter band, Δf, and the output intensity difference between K-th and (K l)-th filters,ΔE, was established in order to show the fine frequency detection ability of the filter bank. This model can also be used to abstract the fundamental frequency of speech and to measure the frequency of pure tone precisely. 相似文献