排序方式: 共有12条查询结果,搜索用时 15 毫秒
1.
基于Drude模型研究了异向介质的色散磁导率对调制不稳定性的影响. 结果表明,在反常色散情形,赝五阶非线性在异向介质的负折射区中增大了调制频谱的范围及增益值,这与常规正折射介质中出现的现象正好相反;自陡峭效应在异向介质中有可能为负值,但无论正负,也无论在正折射区还是负折射区,它都抑制调制不稳定性的产生;二阶非线性色散效应在正、负折射区中分别促进和抑制调制不稳定性的产生. 在正常色散情形,由于二阶非线性色散效应的作用,使本来在常规正折射介质中不可能出现的调制不稳定性现象也能出现,这一特性为在正常色散区形成孤 相似文献
2.
A hybrid structure based on a planar waveguide(PWG) mode coupling a long-range surface plasmon resonance(LRSPR) mode is proposed to enhance the GH shift. Both the PWG mode and LRSPR mode can be in strong resonance, and these two modes can be coupled together due to the normal-mode splitting. The largest GH shift of PWG-coupled LRSPR structure is 4156 times that of the incident beam, which is 23 times and 3.6 times that of the surface plasmon resonance(SPR) structure and the LRSPR structure, respectively. As a GH shift sensor, the highest sensitivity of 4.68 × 10~7λ is realized in the coupled structure. Compared with the sensitivity of the traditional SPR structure, the sensitivity of our structure is increased by more than 2 orders, which theoretically indicates that the proposed configuration can be applied to the field of high-sensitivity sensors in the future. 相似文献
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The optical Tamm state(OTS), which exists generally at the interface between metal and a dielectric Bragg mirror, has been studied extensively in the visible and near infrared spectra. Nevertheless, OTS in the terahertz(THz) region normally receives far less attention. In this Letter, we demonstrate the physical mechanism of OTS at the interface between graphene and a dielectric Bragg mirror in the THz frequency band by applying the transfer matrix method and dispersion characteristics. Based on such mechanisms, we propose an efficient method that can precisely generate and control OTS at a desired angle and frequency. Moreover, we show that the OTS is dependent on the optical conductivity of graphene, making the graphene–dielectric-Bragg-mirror a good candidate for dynamic tunable OTS device in the THz frequency range. 相似文献
5.
基于Drude模型研究了异向介质的色散磁导率对调制不稳定性的影响. 结果表明,在反常色散情形,赝五阶非线性在异向介质的负折射区中增大了调制频谱的范围及增益值,这与常规正折射介质中出现的现象正好相反;自陡峭效应在异向介质中有可能为负值,但无论正负,也无论在正折射区还是负折射区,它都抑制调制不稳定性的产生;二阶非线性色散效应在正、负折射区中分别促进和抑制调制不稳定性的产生. 在正常色散情形,由于二阶非线性色散效应的作用,使本来在常规正折射介质中不可能出现的调制不稳定性现象也能出现,这一特性为在正常色散区形成孤
关键词:
异向介质
调制不稳定性
色散磁导率
二阶非线性色散 相似文献
6.
利用F-函数扩展法求解超介质中的超短脉冲传输方程, 探讨了超介质中的反常自陡效应和特有的二阶非线性色散效应所导致的新的孤子现象和规律. 结果表明, 正折射区的二阶非线性色散效应可以代替线性色散效应形成亮孤子; 正、负折射区的反常自陡效应由于其符号可改变, 从而可在特定条件下分别在反常色散和正常色散区形成有别于常规介质的亮、暗孤子; 反常自陡效应的符号或者反常自陡效应和三阶线性色散效应的相互比较关系能够控制亮、暗孤子中心的漂移方向.
关键词:
孤子
超介质
F-函数扩展法 相似文献
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Enhancement and control of the Goos-H?nchen shift by nonlinear surface plasmon resonance in graphene
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The Goos-H?nchen(GH) shift of graphene in the terahertz frequency range is investigated, and an extremely high GH shift is obtained owing to the excitation of surface plasmon resonance in graphene in the modified Otto configuration.It is shown that the GH shift can be positive or negative, and can be enhanced by introducing a nonlinearity in the substrate.Large and bistable GH shifts are demonstrated to be due to the hysteretic behavior of the reflectance phase. The bistable GH shift can be manipulated by changing the thickness of the air gap and the Fermi level or relaxation time of graphene. 相似文献
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10.
Energy transfer probability in organic electrophosphorescence device with dopant 总被引:1,自引:0,他引:1
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Based on the energy transfer process from host to dopant in an organic
electrophosphorescent (EP) device, the expression of energy transfer
probability ($\eta )$ between the host (TPD) and guest (Ir(ppy)$_{3})$ EP
systems was proposed. The results show that: ({1}) The rate of the triplet
energy transfer ($K_{\rm HG}$ and $K_{\rm GH})$ increases exponentially with
increasing donor-acceptor molecular distance ($R$), whereas decreases as the
intermolecular distance ($R_{\rm HH})$ increases from 0.8 to 2.4 nm.
Furthermore, $K_{\rm GH}$ changes more quickly than $K_{\rm HG.}$ ({2}) The energy
transfer probability ($\eta )$ increases as $R$ reduces, and the $R_{\rm HH}$
changes can be safely neglected for $R<$0.9 nm. The situation changes for
0.9nm$ < R < 1.1$nm, $R_{\rm HH }$ ($<1$nm) plays an essential role when
$\eta $ changes
and increases with the latter. However, if $R > 1.1$nm, the transfer
probability will be below zero. Here, the energy transfer principle may be
less important, and the high electroluminescence (EL) quantum efficiency of
phosphorescent system will be attributed to the direct electron-hole
recombination in phosphorescent molecules. ({3}) The $\eta $ will increase when the
Forster radius ($R_{0})$ increases or Gibb's energy decreases. 相似文献