Author Affiliations
Abstract
1 School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
2 The 28th Research Institute of China Electronics Technology Group Corporation, Nanjing 210007, China
3 College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
4 Collaborative Innovation Center of Advanced Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
Photonic nanojets (PNJs) are subwavelength jet-like propagating waves generated by illuminating a dielectric microstructure with an electromagnetic wave, conventionally a linearly polarized plane wave. Here, we study the donut-like PNJ produced when a circularly polarized vortex beam is used instead. This novel PNJ also has a reverse energy flow at the donut-like focal plane depending on both the optical vortex topological charge and microsphere size. Our tunable PNJ, which we investigate numerically and analytically, can find applications in optical micromanipulation and trapping.
photonic nanojet optical vortex reverse energy flow Chinese Optics Letters
2021, 19(10): 102602
Author Affiliations
Abstract
National Laboratory of Solid Microstructure and School of Physics, Nanjing University, Nanjing 210093, China
We develop a method for completely shaping optical vector beams with controllable amplitude, phase, and polarization gradients along three-dimensional freestyle trajectories. We design theoretically and demonstrate experimentally curvilinear Poincaré vector beams that exhibit high intensity gradients and accurate state of polarization prescribed along the beam trajectory.
laser beam shaping polarization diffraction Chinese Optics Letters
2021, 19(3): 032602
1 南开大学物理科学学院,弱光非线性光子学教育部重点实验室, 天津 300071
2 南京大学固体微结构物理国家重点实验室,人工微结构科学与技术协同创新中心, 江苏 南京 210093
3 曲阜师范大学物理工程学院,山东省激光偏光与信息技术重点实验室, 山东 曲阜 273165
作为光的一个基本属性,偏振态提供的自由度对光场调控具有重要作用。具有空间结构偏振态分布的矢量光场因其具有不同于传统标量光场的独特性质而被应用于诸多领域,但矢量光场的早期研究主要集中于柱对称的局域线偏振矢量光场。近年来,偏振态分布更加丰富的新型矢量光场逐渐得到关注,这些新型矢量光场的出现丰富了矢量光场的种类并提供了新的调控自由度,被应用于焦场调控、光学微加工、光学微操纵和光信息传输等领域。综述了近年来出现的新型矢量光场,包括柱坐标系中的杂化偏振矢量光场、庞加莱球相关的矢量光场、阵列矢量光场、多奇点矢量光场和其他非柱对称的矢量光场,介绍了其进展、设计方案、实验生成、性质和相关应用。
物理光学 偏振态 矢量光场 光场调控 庞加莱球 奇点
Author Affiliations
Abstract
National Laboratory of Solid Microstructure and School of Physics, Nanjing University, Nanjing 210093, China
We propose and simulate a method for generating a three-dimensional (3D) optical cage in the vicinity of focus by focusing a double-ring shaped radially and azimuthally polarized beam. Our study shows that the combination of an inner ring with an azimuthally polarized field and an outer ring with a radially polarized field and a phase factor can produce an optical cage with a dark region enclosed by higher intensity. The shape of the cage can be tailored by appropriately adjusting the parameters of double-mode beams. Furthermore, multiple 3D optical cages can be realized by applying the shift theorem of the Fourier transform and macro-pixel sampling algorithm to a double-ring shaped radially and azimuthally polarized beam.
050.1960 Diffraction theory 260.5430 Polarization Chinese Optics Letters
2018, 16(3): 031405
Author Affiliations
Abstract
1 Nanjing National Laboratory of Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
2 School of Physics, Nankai University, Tianjin 300071, China
An ultrabroadband supercontinuum (SC) is demonstrated in a pure silica photonic crystal fiber (PCF) pumped by quasi-continuous wave nanosecond-long pulses at 1,064 nm. The generated SC spectra extending from 450 to at least 2,400 nm have the salient feature of a short wavelength regime below the pump wavelength, which is much higher in intensity than the long-wavelength over the pump wavelength. The influence of pump power and repetition rates on SC generation (SCG) is explored. Results suggest that this pump source has both the advantages of short-pulse and continuous-wave pumps for SCG.
光子晶体光纤 超连续 纳秒长脉冲 140.0140 Lasers and laser optics 190.0190 Nonlinear optics Chinese Optics Letters
2011, 9(7): 071405
Author Affiliations
Abstract
1 Nanjing National Laboratory of Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
2 School of Physics and Key Laboratory of Weak Light Nonlinear Photonics, Nankai University, Tianjin 300071, China
3 State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
An interesting reflection phenomenon in a dual metal grating (DMG) structure is studied, which is related to the competition between Fabry-Perot (F-P) resonance effect and evanescent-field coupling effect inside the gap between the two composing single metal gratings. This competition leads to high angular sensitivity in response to the refractive index variation of the sample solution in the gap. A reflex optical sensor with high sensitivity based on DMG for detecting the change in refractive index is proposed and its performance theoretically is discussed.
金属双栅 反射谱 角度灵敏度 光学传感器。 050.2770 Gratings 260.2110 Electromagnetic optics 280.4788 Optical sensing and sensors Chinese Optics Letters
2011, 9(6): 060501
提出一种基于模式展开和最小二乘拟合的算法,可以从大剪切量差分波前快捷地重建原始的二维波前。在傅里叶模式展开理论的基础上,从横向剪切干涉获得的差分波前,通过最小二乘拟合,可以计算出待测波前的傅里叶变换系数,重建出原始波前。针对大剪切量带来的差分相位数据维数减小的问题,提出了数据预处理方法。这个算法解决了已有的傅里叶模式估计理论中要求剪切量等于采样间隔的限制,可以应用于大剪切量干涉条件下的二维波前重建。
傅里叶光学 剪切干涉 波前重建 傅里叶变换
在傅里叶变换型磁光谱仪中,起偏器和检偏器的初始方位通常需要在测量前预先定位。提出了一种不需要专门对起偏器和检偏器定位即可完成磁光谱的测量计算的新方法,该方法可以计算出起偏器和检偏器的初始角度值,从而进行自动校准。推导了检偏器旋转角度偏差导致磁光偏转角测量误差的理论公式,并进行了数值分析,给出了测量误差与旋转步数的关系,数值结果表明检偏器角度偏差引起的误差与步数的平方根成反比关系。还给出了一个钴膜样品的磁光克尔角随外加磁场变化的实测曲线。
测量 磁学性质 磁光效应 傅里叶变换 误差分析
1 南京大学物理系, 南京 210093
2 信息产业部电子14所, 南京 210013
提出了一种可以快捷地重建原始的二维波前的新算法。对于分别在相互垂直方向上横向剪切干涉获得的两个差分波前，用快速傅里叶变换首先计算出待测原始波前在x和y方向的估计分布，然后利用误差计算的最小二乘法进行二维拟合，可以恢复出待测波前的二维分布。提出的理论可以应用于剪切量大于1个采样间隔的二维波前重建问题，解决了已有的二维剪切干涉波前重建技术中要求剪切量等于采样间隔的限制。研究了剪切量和噪声对重建精度的影响，和其它算法进行了比较，给出了数值实验结果和分析讨论。结果表明该算法速度快，对噪声有较强的抵抗力，有望在实际的剪切干涉测量中获得应用。
光学测量 干涉 波前重建 剪切干涉 最小二乘法
