Non Mechanical, High-speed, High Turbulence Compensation System Optimized for Optical Ground Stations based on Multi-Plane Light Conversion 

Authors: Antonin Billaud, Cédric Dautancourt, Tanguy Luttman, Claire Autebert, Thibault Michel, Pu Jian, Olivier Pinel, Guillaume Labroille 

Cailabs, Rennes, FRANCE

Abstract

Space-to-ground laser communication is booming with high throughput and stealthy communication without frequency allocation. However, laser communication becomes truly competitive compared with RF at 10 Gbps and beyond. At this rate, fiber components, requiring SMF coupling, and thus turbulence mitigation become necessary for any communication through the atmosphere. Based on Cailabs’ core technology, Multi-Plane Light Conversion (MPLC), Cailabs is developing an industrial turbulence mitigation product fully dedicated to lasercom. The TILBA-ATMO solution is based on a spatial mode decomposition of the turbulent beam thanks to a MPLC spatial demultiplexer, followed by a coherent beam recombiner based on Photonics Integrated Chip (PIC). Previous work has shown the proof of concept of the 8-mode version, demonstrating its capability for low turbulence or small pupils (D/r0 < 7) up to 100 Gbps DP-QPSK. However, a larger number of spatial modes needs to be collected and recombined in order to have relevant turbulence mitigation in the context of an Optical Ground Station (OGS) with a large input telescope (diameter > 40 cm). In this paper, we show that a system collecting 45 spatial modes demonstrates performances in par with the needs of an OGS designed for receiving signal from a Low-Earth Orbit satellite at 10 Gbps. We show the performances of the new TILBA-ATMO with a 45-mode MPLC and a 45-channel PIC-based optical recombiner.