空间相关对偏振辐射光谱特性的影响

$α$-MoO$_3$/$β$-Ga$_2$O$_3$ 扭曲双层结构中高圆偏振热辐射的优化

Optimization of highly circularly polarized thermal radiation in $α$-MoO$_3$/$β$-Ga$_2$O$_3$ twisted layers

该研究提出一种利用低对称性材料各向异性的双层结构，通过调节层间晶轴相对倾斜，实现高圆偏振度（>0.85）窄带红外热辐射，为无光刻红外生物传感热源奠定基础。

氮气中飞秒laser灯丝的外部种子后向激光辐射

Externally seeded backward lasing radiation from femtosecond laser filament in nitrogen gas

最近，S. Mitryukovskiy等人提出的实验证据表明，在337 nm处的后向受激辐射可以从由圆偏振800 nm飞秒脉冲泵浦的氮气中的等离子体细丝获得（Opt. Express，22，12750（2014））。在这里，我们报告说，这种反向受激辐射的种子脉冲的存在下，增强了16倍。这种增强的受激辐射可以是线性或圆偏振的，由播种脉冲决定，这与没有播种脉冲的ASE的非偏振性质不同。我们还测量了空间分布并估计了辐射的能量。这种播种效应明确地证实了等离子体细丝内氮分子的C3-Hu和B3-Hg态之间存在粒子数反转，并提供了一种可能的解决方案来控制这种后向受激辐射的性质。

利用磁化等离子体中径向极化激光脉冲生成方位极化太赫兹辐射

Azimuthally polarized terahertz radiation generation using radially polarized laser pulse in magnetized plasma

研究通过洛伦兹力、连续性方程和麦克斯韦方程分析径向极化激光脉冲在磁化等离子体中的传播，发现生成等幅的横向电磁场构成太赫兹辐射场，并通过PIC模拟验证了辐射场的传播和参数对幅度的影响。

Improper statistics of the radiation from a randomly rotating source

Our earlier work [J. Opt. 19. (2017) 0905603] showed that, in contrast to the four parameters of the traditional Stokes vector description of the statistics of the partially polarized light, the complete second-order statistics of the narrow-band polarized wave is characterized by thirteen parameters. Here we analyze the second-order statistics of the radiation from a randomly rotating source of the electromagnetic radiation, and show that it includes a covariance of the right and left circular polarizations that is not captured by the Stokes vector formalism. We illustrate this finding on a s…

Polarization singularities in the self-focusing of an elliptically polarized laser beam in an isotropic phase of cholesteric liquid crystal close to the temperature of phase transition

The work is devoted to the self-action of laser beams propagating in the isotropic phase of a cholesteric liquid crystal near the transition temperature to the mesophase in a wide range of parameter values characterizing the nonlocality of the nonlinear optical response of the medium, defocusing in the medium, the power of incident laser radiation and diffraction in the liquid crystal. The origin of the primary singularities of both polarization components of radiation in a wide range of parameters of radiation and the medium is investigated for different values of the parameter characterizing…

利用圆极化高次谐波辐射的纳米磁成像

Nanoscale Magnetic Imaging using Circularly Polarized High-Harmonic Radiation

这项工作展示了使用明亮的圆偏振高谐波辐射的纳米级磁成像。我们利用Co/Pd多层膜结构中蠕虫状磁畴的磁光对比度，通过无透镜成像获得定量的振幅和相位图。采用全息掩模增强的迭代相位重建技术，实现了49 nm的衍射极限空间分辨率。利用高次谐波的独特相干性，这种方法将促进超快磁化动力学的定量，元素特异性和空间分辨研究，推进纳米磁性的基础和应用方面。

均匀磁场和包络调制圆极化laser场中的汤姆逊后向散射

Thomson backscattering in combined uniform magnetic and envelope modulating circularly-polarized laser fields

本文详细研究了均匀磁场和余弦包络圆偏振激光场联合作用下的汤姆逊后向散射谱。随着包络调制的引入，由于强非线性相互作用，辐射光谱表现出高度的复杂性。另一方面，四个基本法律有关的辐射光谱的标度不变性的解析揭示和数值验证。它们分别是辐射能量与初始轴向动量和激光强度的精确$6$次幂和近似负$6$次幂的定律，以及一个重要的自相似定律，即当环形激光频率、包络调制频率和修正的回旋频率同时增加一个因子时，辐射能量将增加该因子的二次幂而不改变光谱的形状。应用这些定律，特别是最后一个定律，可以获得高得多的辐射能量，并且可以精确地调谐最大辐射出现的谐波而不改变其振幅。这些发现为在医学、通信、天体物理学和安全等许多领域推进辐射技术提供了一种可能的方法。

Broadband circularly polarized thermal radiation from magnetic Weyl semimetals

We numerically demonstrate that a planar slab made of magnetic Weyl semimetal (a class of topological materials) can emit high-purity circularly polarized (CP) thermal radiation over a broad mid- and long-wave infrared wavelength range for a significant portion of its emission solid angle. This effect fundamentally arises from the strong infrared gyrotropy or nonreciprocity of these materials which primarily depends on the momentum separation between Weyl nodes in the band structure. We clarify the dependence of this effect on the underlying physical parameters and highlight that the spectral …

Anisotropic and tunable optical conductivity of a two-dimensional semi-Dirac system in the presence of elliptically polarized radiation

We investigate the effect of ellipticity ratio of the polarized radiation field on optoelectronic properties of a two-dimensional (2D) semi-Dirac (SD) system. The optical conductivity is calculated within the energy balance equation approach derived from the semiclassical Boltzmann equation. We find that there exists the anisotropic optical absorption induced via both the intra- and interband electronic transition channels in the perpendicular $xx$ and $yy$ directions. Furthermore, we examine the effects of the ellipticity ratio, the temperature, the carrier density, and the band-gap parameter…

Resonance pressure of electromagnetic radiation on metal nanoparticle

The influence of the electromagnetic irradiation pressure on a spheroidal metallic nanoparticle at the frequencies close to the surface plasmon vibrations has been considered. With the action of the radiation pressure, the polarizability of metal nanoparticle becomes a tensor quantity. The expressions for the resonance pressure components for the cases of plane-polarized and circularly polarized light have been derived. We have demonstrated that the resonance pressure can substantially depend on the shape of a non-spherical nanoparticle and its orientation with respect to the direction of ligh…

Universal spin-resolved thermal radiation laws for nonreciprocal bianisotropic media

A chiral absorber of light can emit spin-polarized (circularly polarized) thermal radiation based on Kirchhoff's law which equates spin-resolved emissivity with spin-resolved absorptivity for reciprocal media at thermal equilibrium. No such law is known for nonreciprocal media. In this work, we discover three spin-resolved Kirchhoff's laws of thermal radiation applicable for both reciprocal and nonreciprocal planar media. In particular, these laws are applicable to multi-layered or composite slabs of generic bianisotropic material classes which include (uniaxial or biaxial) birefringent crysta…