Turbulence-resilient pilot-assisted self-coherent free-space optical communications using automatic optoelectronic mixing of many modes

Runzhou Zhang*, Nanzhe Hu, Huibin Zhou, Kaiheng Zou, Xinzhou Su, Yiyu Zhou, Haoqian Song, Kai Pang, Hao Song, Amir Minoofar, Zhe Zhao, Cong Liu, Karapet Manukyan, Ahmed Almaiman, Brittany Lynn, Robert W. Boyd, Moshe Tur, Alan E. Willner

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

In free-space optical communications that use both amplitude and phase data modulation (for example, in quadrature amplitude modulation (QAM)), the data are typically recovered by mixing a Gaussian local oscillator with a received Gaussian data beam. However, atmospheric turbulence can induce power coupling from the transmitted Gaussian mode to higher-order modes, resulting in a significantly degraded mixing efficiency and system performance. Here, we use a pilot-assisted self-coherent detection approach to overcome this problem. Specifically, we transmit both a Gaussian data beam and a frequency-offset Gaussian pilot tone beam such that both beams experience similar turbulence and modal coupling. Subsequently, a photodetector mixes all corresponding pairs of the beams’ modes. During mixing, a conjugate of the turbulence-induced modal coupling is generated and compensates the modal coupling experienced by the data, and thus the corresponding modes of the pilot and data mix efficiently. We demonstrate a 12 Gbit s−1 16-QAM polarization-multiplexed free-space optical link that is resistant to turbulence.

Original languageEnglish
Pages (from-to)743-750
Number of pages8
JournalNature Photonics
Volume15
Issue number10
DOIs
StatePublished - Oct 2021

Fingerprint

Dive into the research topics of 'Turbulence-resilient pilot-assisted self-coherent free-space optical communications using automatic optoelectronic mixing of many modes'. Together they form a unique fingerprint.

Cite this