涡旋光束的几何坐标变换技术及应用研究进展(特邀)

Research progress on technologies and applications of geometric coordinate transformation of vortex beam(Invited)

涡旋光场因其具有光学轨道角动量(Orbital angular momentum,OAM)而倍受关注。OAM这一独特物理特征赋予了涡旋光场一个无限高维的空间自由度,同时也引发了光场奇特的干涉、衍射、传输等性质。OAM识别和探测技术的发展是涡旋光从基础研究走向应用的关键。文中聚焦于OAM探测领域的一个重点研究方向——涡旋光几何坐标变换技术。详细介绍了该技术的基本原理、优势特点、研究进展和应用情况。涡旋光几何坐标变换是指通过特殊的调制相位设计,使涡旋光束的空间几何结构发生特殊的变化,从而可通过简单透镜聚焦等方法实现OAM模式的识别、分选等。相较于传统的涡旋光识别和探测技术,涡旋光的几何坐标变换这一新兴技术具有器件无源、无能量损耗、结构紧凑、价格低廉等突出优势,成为涡旋光的空间分离和解复用的高效有力工具,为涡旋光束在经典/量子态密度测量、OAM乘除法器、经典光通信和量子纠缠等前沿应用提供了全新的研究平台,蕴含巨大的发展潜力,具有广阔的发展空间。

Vortex light fields have attracted much attention,due to their nature of optical orbital angular momentum(OAM).The unique physical characteristics of OAM endow the vortex beam with an infinite degree of freedom in high-dimensional space,and at the same time,it also brings the unusual properties of interference,diffraction and transmission to the light field.OAM identification and detection technologies are critical to development of vortex beam from fundamental research towards practical applications.The paper focused on the geometric coordinate transformation of vortex beam,as one of important research directions in the domain of OAM detection,and reviewed the technology in detail in terms of its principles,features,research progresses and applications.Geometric coordinate transformation of vortex beam refered to transforming the whole geometric structure of vortex beam by a specialized modulation phase design,which could sort and detect OAM of vortex beam easily.Compared with traditional sorting and detecting technologies,the geometric coordinate transformation technology was favored with the advantages of passive device,no energy loss,compact structure and low cost.This unique method had become an efficient and powerful tool for the spatial separation and demultiplexing of vortex beams,and had provided a new platform for advanced applications such as classical or quantum density measurement,OAM multiplier and divider,classical optical communication and quantum entanglement,showing great potentials and broad development prospect.