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在将介观无损耗传输线量子化的基础上, 研究了真空态和压缩真空态下传输线中电流和电流梯度的量子涨落. 着重分析了传输线与一般LC电路量子涨落的差异.
关键词:
介观无损耗传输线
真空态
压缩真空态
量子涨落 相似文献
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从耗散传输线的经典运动方程出发,将传输线中的单模信号进行量子化,研究了传输线在激发相干态下的量子效应.结果表明,传输线的量子涨落不仅与电路参数和电路的状态有关,还与传输线的位置有关.
关键词:
介观传输线
耗散
单模
激发相干态 相似文献
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利用热场动力学的方法研究了介观RLC电路在具有热噪声的真空态下电荷和磁通(电流)的量子涨落.从而得到了有限温度下这一电路在热真空态下的量子涨落与温度的关系.结果表明,介观RLC电路的量子涨落不仅与电路中的元件参量和电路的共振频率ω有关,而且与温度T有关.温度越高,介观RLC电路的量子噪声越大
关键词:
介观RLC电路
热真空态
量子涨落 相似文献
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本文研究了在两个耦合的量子点和腔QED系统中的双模激子的压缩性质.讨论了不同的初始光场对双模激子的正常压缩与和压缩的影响.计算表明,当初始态光场制备在相干态时,双模激子既不存在正常压缩,也不存在和压缩,这说明双模激子振辐的两个正交分量具有相同的量子涨落;然而,当初始腔场处于压缩真空态时,无论是正常压缩还是和压缩,双模激子振辐的两个正交分量总有一个存在压缩.这意味着量子噪声能被有效的得到抑制.此外,两种情形下的最大压缩都由初始腔场的压缩因子r决定.经过比较,我们还发现双模激子的正常压缩比和压缩大. 相似文献
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提出一种从低频混响信号中提取简正波衰减系数的方法。利用简正波过滤技术对垂直阵混响信号进行分析,获得单阶简正波混响声场。假设海底反向散射矩阵可分离,从单阶简正波平均混响强度中提取出有效海底反向散射矩阵元素,最后利用不同距离上的有效海底反向散射矩阵元素计算出简正波的衰减系数。利用该方法从混响信号中提取出的简正波衰减系数预报的声传播损失和相同海域实测声传播损失一致。该简正波衰减系数提取方法有效避免了海底散射衰减和简正波传播衰减耦合的问题,同时对海底参数反演和水声环境的快速评估也具有重要的意义。 相似文献
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Kambiz Abedi Vahid Ahmadi Mohammad Kazem Moravvej-Farshi 《Optical and Quantum Electronics》2009,41(10):719-733
The finite difference method is exploited for a full-vectorial analysis of mushroom-type waveguides for traveling wave electroabsorption
modulators (TWEAM) based on asymmetric intra-step-barrier coupled double strained quantum wells (AICD-SQW). In this analysis,
the discontinuities of the normal components of the electric field across abrupt dielectric interfaces which are known as
the limitations of scalar and semivectorial approximation methods are considered. The optical field distributions in mushroom-type
TWEAM based on AICD-SQW and conventional ridge-type TWEAM of the same active region for 1.55 μm operation are presented. The
important parameters in the high-frequency TWEAM design such as optical effective index which defines optical velocity and
transverse mode confinement factor are calculated. Then, the transmission line microwave properties (microwave index, microwave
loss, and characteristic impedance) of TWEAMs are obtained. The modulation response of mushroom-type TWEAM is calculated using
circuit model by considering interaction between microwave and optical fields in waveguide and compared with conventional
ridge-type TWEAM. It is found that increasing the width of p-cladding layer with the same i-layer to reduce the resistance
in p-i-n mushroom-type waveguide of TWEAM based on AICD-SQW can improve the microwave propagation loss and thus the high-speed
electro-optical response. 相似文献
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Magnetic damping has been studied in magnetic double layers using a network analyzer (NA) with a coplanar transmission line. The magnetic films consisted of ultrathin crystalline films of Fe separated by an Au spacer. The films were deposited on GaAs(0 0 1) substrates using the molecular beam epitaxy (MBE) technique. NA-ferromagnetic resonance (NA-FMR) measurements were carried out along the magnetic hard axis, allowing one to follow the frequency FMR linewidth down to the 1 GHz range of frequencies. It will be shown that the FMR linewidth in the NA-FMR measurements is not entirely described by Gilbert damping. The additional contribution in the frequency linewidth increases with decreasing frequency, and is most likely caused by dipolar fields associated with an inhomogeneous RF field around the coplanar transmission line. 相似文献
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An improved transmission line model to study the thermal effects in semiconductor laser diodes is reported in this paper.
The temperature effects in the laser characteristics are obtained by incorporating temperature dependent gain and carrier
density equations for the laser cavity. These primary factors are introduced in the regular transmission line laser model
to estimate the static and dynamic characteristics of an 1.3μm InGaAsP double heterostructure laser diode. The results show
good agreement with the experimental observation and solution of rate equations referred in the literature. The key feature
of this model is that it provides the laser spectra at various temperatures. Based on the model, time dependent evolution
of optical spectrum, temperature dependent optical output and frequency chirp are evaluated. Further the distribution of photon
and electron density within the cavity is also determined. 相似文献
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指出了磁绝缘线振荡器(MILO)微波提取结构传统设计方法中可能存在的问题。通过高频电磁软件模拟得到当微波提取结构具有不同特征阻抗时TEM模式功率传输效率在MILO工作频点附近的频率响应规律。模拟结果表明,当MILO阻抗较高时,用传统方式设计的微波提取结构不能满足TEM模式传输的要求。为了解决高阻抗情况下TEM模式的传输困难,提出并讨论了阶梯负载的设计方案。进一步模拟结果表明,阶梯负载克服了TEM模式的传输困难,提高了微波提取结构对MILO频率漂移的适应能力。 相似文献
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In this work we report new experimental results on nonlinear excitation of magnetoelastic (ME) modes in layered YIG/GGG waveguide structures at GHz frequencies, obtained by a guided-wave light scattering technique. It is shown that the fundamental spin-dipole wave (SDW) mode induces a secondary microwave field at double frequency that can efficiently excite shear elastic modes of the structure. The distinctive feature of a mechanism for ME coupling proposed is that it is free from the selection rules and provides continuous excitation of elastic modes within a wide frequency range by means of the standard microstripe line excitation system. 相似文献
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传统的线束串扰模型只是在系统内共模激励的基础上建立的, 没有考虑系统间差模激励下线束串扰的情况. 针对差模激励下系统独立回路间线束串扰的物理问题, 提出了一种基于多导体传输线理论的差模激励新型线束串扰的计算方法.该方法根据差模激励下线间的耦合机理, 利用传输线传播横向电磁模式得到新型三导体传输线寄生参数电路及数学矩阵模型, 通过镜像法以及诺埃曼公式推导出寄生参数的计算公式, 并在频域内得到新型线束串扰的链参数矩阵方程, 根据新型差模串扰模型始端、终端边界条件最终得到串扰电压的频域解.以差模激励下平行双线回路对其他回路受扰线的串扰为例, 通过仿真受扰线不同布置情况下的串扰电压, 得到了差模激励源的线束间串扰的物理规律, 即受扰线位于差模回路之间时所受的串扰要远大于位于回路外时所受的串扰, 并验证所提出的模型及方法可以计算不同频率差模激励引起的干扰. 利用解析的方法解决了线束串扰中差模激励下的导线串扰问题, 为实际中如大量导线的捆扎以及导线干扰的预测等电磁兼容问题提供了理论依据, 具有指导意义, 完善了多导体传输线理论在线束串扰中的应用. 相似文献