Modal properties of a beam carrying OAM generated by a circular array of multiple ring-resonator emitters
Abstract
We investigate the modal properties of a beam carrying orbital angular momentum (OAM) generated by a circular array (ring) of multiple micro-ring emitters (rings) analytically and via simulation. In such a “ring-of-rings” structure, N emitters generate N optical vortex beams with the same OAM-order l 0 at the same wavelength. The output beam is a coherent combination of the N vortex beams located at different azimuthal positions, having the same radial displacement. We derive an analytical expression for the output optical field and calculate the OAM-order power spectrum of the generated beam. The analytical expression and simulation results show that (1) the OAM spectrum of the output beam composes equidistant OAM spectral components, symmetrically surrounding l 0 with a spacing equal to N ; (2) the envelope of the OAM spectrum broadens with an increased radius of the circular array or the value of l 0 ; and (3) the OAM components of the generated beam could be tuned either by changing the value of l 0 , corresponding to different spectrum envelopes, or by adding different linear phase delays to the micro-ring emitters, which does not affect the envelope of the OAM spectrum.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 17, 2021
- Source ID
- 10.1364/ol.435916
Entities
People
- Alan E. Willner
- Brittany Lynn
- Cong Liu
- Hao Song
- Haoqian Song
- Huibin Zhou
- Kai Pang
- Kaiheng Zou
- Moshe Tur
- Nanzhe Hu
- Robert Bock
- Runzhou Zhang
- Xinzhou Su
- Zhe Zhao
Organizations
- Air Force Research Laboratory
- Naval Information Warfare Systems Command
- Tel Aviv University
- University of Southern California