Affiliation:
1. Boston University
2. Tampere University
3. Université de Franche-Comté
Abstract
Light beams carrying orbital angular momentum (OAM) in free space or
within optical fibers have a wide range of applications in optics;
however, exciting these modes with both high purity and low loss
generally requires demanding optimization of excitation conditions in
a high dimensional space. Furthermore, mechanical drift can
significantly degrade the mode purity over time, which may limit
practical deployment of OAM modes in concrete applications. Here,
combining an iterative wavefront matching approach and a genetic
algorithm, we demonstrate rapid and automated excitation of OAM modes
with optimized purity and reduced loss. Our approach allows for
systematic computational realignment of the system enabling drift
compensation over extended durations. Our experimental results
indicate that OAM purity can be optimized and maintained over periods
exceeding 24 h, paving the way for the applications of stable OAM
beams in optics.
Funder
Research Council of Finland
Office of Naval Research