RESUMO
Propagation of laser light is distorted in the presence of atmospheric turbulence. This poses an issue for sensing, free-space optical communications, and transmission of power. The presented system offers a novel solution to mitigate the effects of turbulence. By rapidly probing a turbulent volume by varying a beam's spatial and phase characteristics, the best transmission mode can be determined and updated in real time. Unlike a traditional tip-tilt system, this scheme is fully electronic, and has a scalable architecture to leverage multiple optical transmission paths simultaneously. This optical control system greatly improves power efficiency and successful recovery of data through environments with strong turbulence.
RESUMO
Orbital angular momentum (OAM) is a potential tool for remote sensing applications since amplitude/phase distributions can be decomposed into an OAM basis for analysis. We demonstrate the generation of a spatially asymmetric perfect vortex (APV) basis based on a pulsed 2D HOBBIT (Higher Order Bessel Beams Integrated in Time) system using two acousto-optic deflectors and optical coordinate transformation optics. Results are demonstrated for numerous radii and OAM charges as high as 20, with switching speeds greater than 400 kHz. The spatial APV basis is used to design different types of pulse trains for amplitude object pattern recognition and phase object wavefront sensing. Experimental results of sensing are provided for an amplitude object and a phase object to demonstrate the feasibility of the spatial APV on remote sensing tasks.