作者机构:
[Wang, Youwen; Dai, Zhiping; Ling, Xiaohui] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Yang, Zhenjun; Li, Xingliang; Zhang, Shumin; Pang, Zhaoguang] Hebei Normal Univ, Coll Phys & Informat Engn, Hebei Adv Thin Films Lab, Shijiazhuang 050024, Peoples R China.
通讯机构:
[Yang, Zhenjun] H;Hebei Normal Univ, Coll Phys & Informat Engn, Hebei Adv Thin Films Lab, Shijiazhuang 050024, Peoples R China.
摘要:
<jats:title>Abstract</jats:title><jats:p>The approximate analytical expressions of tripole-mode and quadrupole-mode solitons in (1 + 1)-dimensional nematic liquid crystals are obtained by applying the variational approach. It is found that the soliton powers for the two types of solitons are not equal with the same parameters, which is much different from their counterparts in the Snyder-Mitchell model (an ideal and typical strongly nolocal nonlinear model). The numerical simulations show that for the strongly nonlocal case, by expanding the response function to the second order, the approximate soliton solutions are in good agreement with the numerical results. Furthermore, by expanding the respond function to the higher orders, the accuracy and the validity range of the approximate soliton solutions increase. If the response function is expanded to the tenth order, the approximate solutions are still valid for the general nonlocal case.</jats:p>
摘要:
In high-power laser system such as Petawatt lasers, the laser beam can be intense enough to result in saturation of nonlinear refraction index of medium. Based on the standard linearization method of small-scale self-focusing and the split-step Fourier numerical calculation method, we present analytical and simulative investigations on the hot-image formation in cascaded saturable nonlinear medium slabs, to disclose the effect of nonlinearity saturation on the distribution and intensity of hot images. The analytical and simulative results are found in good agreement. It is shown that, saturable nonlinearity does not change the distribution of hot images, while may greatly affect the intensity of hot images, i.e., for a given saturation light intensity, with the intensity of the incident laser beam, the intensity of hot images firstly increases monotonously and eventually reaches a saturation; for the incident laser beam of a given intensity, with the saturation light intensity lowering, the intensity of hot images decreases rapidly, even resulting in a few hot images too weak to be visible.
摘要:
In high-power laser system such as Petawatt lasers, the laser beam can be intense enough to result in saturation of nonlinear refraction index of medium. We present an analytical and simulative investigation of hot image formation in an intense laser beam through a saturable nonlinear medium slab based on Fresnel-Kirchhoff diffraction integral and the standard split-step Fourier method. The analytical results are found in agreement with the simulative ones. It is shown that, hot images can still form in an intense laser beam through a saturable nonlinear medium slab, additionally, the saturable nonlinearity does not change the location of hot images, while may decrease the intensity of hot images, i.e., the intensity of hot images decreases with the saturation light intensity lowering, and can stop to increase with the intensity of the incident laser beam heightening due to saturation of nonlinearity. Moreover, variations of intensity of hot images with the obscuration type and the slab thickness are discussed.
关键词:
Spin Hall effect of light;vector beam;spin accumulation
摘要:
We report the demonstration of intrinsic spin Hall effect (SHE) of cylindrical vector beam. Employing a fan-shaped aperture to block part of the vector beam, the intrinsic vortex phases are no longer continuous in the azimuthal direction, and results in the spin accumulation at the opposite edges of the light beam. Due to the inherent nature of the phase and independency of light-matter interaction, the observed SHE is intrinsic. Modulating the topological charge of the vector beam, the spin-dependent splitting can be enhanced and the direction of spin accumulation is switchable.
摘要:
Nanosecond-level pulses of specific shape is usually generated by stacking chirped pulses for high-power inertial confinement fusion driver, in which nonlinear imaging of scatterers may damage precious optical elements. We present a numerical study of the characteristics of nonlinear imaging of scatterers in broadband laser stacked by chirped pulses to disclose the dependence of location and intensity of images on the parameters of the stacked pulse. It is shown that, for sub-nanosecond long sub-pulses with chirp or transform-limited sub-pulses, the time-mean intensity and location of images through normally dispersive and anomalously dispersive self-focusing medium slab are almost identical; While for picosecond-level short sub-pulses with chirp, the time-mean intensity of images for weak normal dispersion is slightly higher than that for weak anomalous dispersion through a thin nonlinear slab; the result is opposite to that for strong dispersion in a thick nonlinear slab; Furthermore, for given time delay between neighboring sub-pulses, the time-mean intensity of images varies periodically with chirp of the sub-pulse increasing; for a given pulse width of sub-pulse, the time-mean intensity of images decreases with the time delay between neighboring sub-pulses increasing; additionally, there is a little difference in the time-mean intensity of images of the laser stacked by different numbers of sub-pulses. Finally, the obtained results are also given physical explanations.
作者:
You Kai-Ming*;Lin Yan-Ling;Wang You-Wen;Chen Lie-Zun;Dai Zhi-Ping;...
期刊:
物理学报,2013年62(14):22-27 ISSN:1000-3290
通讯作者:
You Kai-Ming
作者机构:
[Lin Yan-Ling; Chen Lie-Zun; You Kai-Ming; Wang You-Wen; Dai Zhi-Ping; Lu Shi-Zhuan] Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421002, Peoples R China.
通讯机构:
[You Kai-Ming] H;Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421002, Peoples R China.
关键词:
Dini级数展开;高阶Hankel变换;光束传输
摘要:
基于Dini级数展开, 导出了p(>0)阶准离散Hankel变换(the pth-order quasi-discrete Hankel transform based on Dini series expansion, pDQDHT)算法, 并给出了该算法在光束传输中的应用. 通过不同输入函数分别对pDQDHT算法进行测试及光束通过透镜传输的应用实例, 结果表明: pDQDHT算法不仅精度高于现有的Hankel变换算法, 可以进行多次正、逆变换, 能广泛应用于光束分步传输问题, 而且执行速度也与一般的快速Hankel变换算法相当.