Dynamic spatiotemporal beams that combine two independent and controllable orbital-angular-momenta using multiple optical-frequency-comb lines.

ABSTRACT: Novel forms of beam generation and propagation based on orbital angular momentum (OAM) have recently gained significant interest. In terms of changes in time, OAM can be manifest at a given distance in different forms, including: (1) a Gaussian-like beam dot that revolves around a central axis, and (2) a Laguerre-Gaussian ([Formula: see text]) beam with a helical phasefront rotating around its own beam center. Here we explore the generation of dynamic spatiotemporal beams that combine these two forms of orbital-angular-momenta by coherently adding multiple frequency comb lines. Each line carries a superposition of multiple [Formula: see text] modes such that each line is composed of a different [Formula: see text] value and multiple p values. We simulate the generated beams and find that the following can be achieved: (a) mode purity up to 99%, and (b) control of the helical phasefront from 2?-6? and the revolving speed from 0.2-0.6?THz. This approach might be useful for generating spatiotemporal beams with even more sophisticated dynamic properties.

SUBMITTER: Zhao Z 

PROVIDER: S-EPMC7427811 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature