Generation of X-ray vortex with ultra-long depth of focus using axial line-focused spiral zone plate

来源 :ChineseOpticsLetters | 被引量 : 0次 | 上传用户:breeze_86
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
We propose axial line-focused spiral zone plates (ALFSZPs) for generating tightly focused X-ray vortex beams with ultra-long depth of focus (DOF) along the propagation direction. In this typical design, compared with the conventional spiral zone plates (SZPs) under the same numerical aperture (NA), the DOF of ALFSZPs has been extended to an ultra-length by optimizing the corresponding parameters. Besides, it also exhibits lower side lobes and smaller dark cores in the whole focus volume. The diameters of dark cores increase as the topological charge value increases.
其他文献
基于投影限制集算法(POCS),设计出用一个纯相位调制的衍射光学元件实现控制光波前在三维区域之内的传播,将输入的高斯光束变换为沿纵向调制的等光强的2×2光束阵列。模拟计算表明,该算法在控制光波前传播方面是有效的。
The surface morphology of lateral flow (LF) strip is examined by scanning electron microscope (SEM) and the diffuse reflection of porous strip with or without nanogold particles is investigated. Based on the scattering and absorption of nanogold particles
基于模式截止法,设计了两种超宽带单偏振单模方形阵列液晶填充光子晶体光纤,利用全矢量有限元法分析了光纤纤芯中额外空气孔、纤芯孔间距及纤芯液晶填充孔径对单偏振单模传输特性的影响。所设计的带宽可调谐的超宽带单芯单偏振单模光子晶体光纤,其单偏振单模传输可在0.75~2.59 μm波段范围内调谐,限制损耗低于0.1 dB·km -1对应的单偏振单模传输带宽为970 nm。所设计的另一种光纤是在0.98~1.74 μm波段范围内具有单偏振单模传输特性的双芯光子晶体光纤,将其
将螺旋型液晶看作是N层双折射材料晶片叠合而成,而每层光轴相对于相邻的晶片有一个小的旋转。本文基于矩阵理论,研究了光在螺旋液晶中传输时偏振态的变化。经过详细的数学推导,理论研究表明,线性偏振光经过螺旋液晶后偏振态会发生改变。当满足一定的条件时,线偏振光的偏振方向旋转90°,左旋圆偏振光经过左旋螺旋液晶后转变为右旋圆偏振光。
近年来中红外超快锁模激光器发展极为迅速,有效地推动了中红外超快激光在中红外频率梳和分子光谱学、材料加工和激光手术、分子生物和化学等领域的应用。从近年来中红外超快光纤激光器的进展开始,介绍了该波段各类光纤激光的进展,并分析了如何从动力学调控上实现更窄脉宽、更远波长的技术方案;系统介绍了中红外光纤放大器中啁啾脉冲放大和非线性放大技术。综合来看,中红外超快光纤激光器正处在高速发展阶段,未来具有极高的应用价值。
期刊
We report on the lasing characteristics of a two-color InAs/InP quantum dots (QDs) laser at a low temperature. Two lasing peaks with a tunable gap are simultaneously observed. At a low temperature of 80 K, a tunable range greater than a 20-nm wavelength i
A strain-introduced Mach-Zehnder interferometer (MZI) interleaver on lithium niobate (LiNbO3) is proposed. The structure of the strain-introduced waveguide is designed in detail, and is produced by depositing a SiO2 film on the annea
期刊
本文在多原子强耦合腔-QED系统中,利用脉冲宽度为5 ns的强脉冲光在垂直于腔轴方向直接激发原子,脉冲的峰值功率为40 mW,通过光学腔观测激发原子辐射到腔中的光子获得相应的激发光谱。我们发现当光场频率和原子跃迁失谐±80 MHz时原子激发率达到最大,而在共振时原子激发被抑制。我们建立了脉冲光与三能级原子相互作用的模型,通过缀饰态能够解释此现象。