光学超晶格中涡旋光的产生与调控  

Generation and manipulation of vortex beams in optical superlattice

作　　者：陈琰[1,2,3] 胡小鹏 张勇[1,2] 祝世宁[1,2,3] CHEN Yan;HU Xiaopeng;ZHANG Yong;ZHU Shining(National Laboratory of Solid State Microstructures(Nanjing University),Nanjing 210093,China;College of Engineering and Applied Sciences,Nanjing University,Nanjing 210093,China;School of Physics,Nanjing University,Nanjing 210093,China)

机构地区：[1]固体微结构物理国家重点实验室(南京大学),南京210093 [2]南京大学现代工程与应用科学学院,南京210093 [3]南京大学物理学院,南京210093

出　　处：《哈尔滨工业大学学报》2020年第6期12-20,共9页Journal of Harbin Institute of Technology

基　　金：国家重点研发计划(2017YFA0303700,2019YFA0705000);国家自然科学基金(11674171,91950206)。

摘　　要：携带轨道角动量的光束,又称为涡旋光,因其新奇的相位分布和物理特性,在光学微操控、超分辨成像、高容量光通信和量子信息技术等领域有重要的应用.涡旋光应用于不同场景需要不同的频率,使用基于准相位匹配原理的光学超晶格作为非线性转换晶体,是获得新频率光源的重要手段.涡旋光与介质的非线性相互作用,不仅要考虑常规的能量守恒和线性动量守恒,还需要关注轨道角动量的守恒问题.本文综述了光学超晶格中涡旋光产生和调控方面的研究进展.通过倍频、和频、三倍频和参量下转换等非线性频率转换过程,可以高效的将涡旋光的工作波长拓展到蓝紫直至中红外波段;通过光学超晶格倒格矢的精密设计,可以灵活调控涡旋光非线性频率转换过程中的轨道角动量转移等.基于非线性全息思想设计非线性光子晶体,可以在频率转换的同时调控光场的波前、相位和振幅等物理参量,从而实现涡旋光束的非线性产生;伴随着超晶格制备技术的突破,调控的维度也从二维拓展至三维.光学超晶格中涡旋光产生和调控的研究,可以加深对轨道角动量这一重要物理守恒量的理解,以及推动相关应用研究的进展.Light beams carrying orbital angular momentum(OAM) are called vortex beams. Due to the novel phase distribution and the physical properties, such beams are widely used in optical micro-manipulation, super-resolution imaging, high-capacity communication, and quantum information technologies. As different applications require light sources with different wavelengths, nonlinear frequency conversions in optical superlattice through quasi-phase-matching provide a promising way to extend the wavelength of vortex beams. For the interaction between vortex lights and nonlinear medium, the conservation of energy, linear momentum as well as OAM should be concerned. Herein, recent progress on nonlinear generation and manipulation of optical vortices in optical superlattice is reviewed. Through nonlinear frequency conversion including second and third harmonic generation, sum frequency generation, and frequency down conversion processes, the working wavelength of the vortex beam can be efficiently extended from blue-violet to mid-infrared band. The transfer of OAM in the frequency conversion process can be flexibly controlled by precisely designing the optical superlattice. Designing nonlinear photonic crystals exploiting nonlinear holography, one can modulate the wavefront, phase, and amplitude of the light field during the frequency conversion process, thus the nonlinear generation and manipulation of vortex beam can be realized. With the development of the superlattice fabrication technology, the manipulating dimension of light field has been expanded from two-dimension to three-dimension. Investigations on the generation and manipulation of vortex beams in optical superlattice can deepen the understanding of OAM as well as promote the progress of the related applied research.

关 键 词：光学超晶格 涡旋光 轨道角动量 准相位匹配 非线性全息 

分 类 号：O437[机械工程—光学工程]