Turbulence-Resistant FSO Communication Using a Few-Mode Pre-Amplified Receiver

Leveraging recent advances in space-division multiplexing, we propose and demonstrate turbulence-resistant free-space optical communication using few-mode (FM) pre-amplified receivers. The rationale for this approach is that a distorted wavefront can be decomposed into a superposition of the fundamental Gaussian mode and high-order modes of a few-mode fiber. We present the noise statistics and the sensitivity of the FM pre-amplified receiver, followed by experimental and numerical comparisons between FM pre-amplified receivers and single-mode (SM) pre-amplified receivers with or without adaptive optics. FM pre-amplified receivers for FSO can achieve high sensitivity, simplicity and reliability.