A new class of microcomb: orbital angular momentum frequency comb

Microresonator-based optical Kerr frequency combs (optical microcombs) are broadband and coherent light sources that are deployed in a wide range of applications, including optical communications, LIDAR, optical neural networks, and atomic clocks. Offering coherent equidistant spectral lines, the microcombs are already a powerful tool that revolutionizes various applications. With the development in the field of meta-optics and the emergence of new nonlinear material platforms, this project explores the feasibility of developing a new class of microcomb that can emit a cluster of light not only in the frequency dimension but also in the optical mode dimension (orbital angular momentum (OAM) modes) to further extend the versatility of the microcombs and open new possibilities in communication and quantum applications. The "OAM comb" is uniquely realized by drawing together three emerging optical technologies – (1) optical microcombs, (2) metaoptical waveguides, and (3) OAM of light. In addition, the research will provide a profound knowledge of nonlinear optical dynamics of simultaneous generation of frequency and OAM combs.