Abstract

To achieve a link budget capable of supporting high capacity free space optical communication (FSO), a high transmit power is required. However, the transmitter can become potentially hazardous to the human eye. For a C-band transmitter to be classified as Class 1 eye-safe, the transmit intensity should be limited such that the optical power passing through a 24.5 mm diameter area is below 10 dBm. In this work we used a 9-aperture transmit, single-aperture receive FSO system to reduce the transmit intensity. Wavelength division multiplexed (WDM) signals were divided into 9 groups and transmitted through 9 apertures as separate beams. The apertures were arranged in a 3 x 3 array at a 25 mm pitch, and the transmit power from each aperture was set to 10 dBm. As a validation of the system by numerical simulation of propagation over 220 m, we showed that the additional free space loss due to pointing errors for the beams transmitted through the off-center apertures was less than 7.4 dB, and that using multiple apertures can significantly increase the transmission capacity. In the outdoor demonstration we transmitted 35 WDM 400 Gb/s dual-polarization probabilistically shaped 16-ary quadrature amplitude modulation signals over 220 m. By distributing the WDM channels across the 9 apertures to suit the transmission loss from their positions in the 3 x 3 array, we demonstrated error-free real-time transmission of a record capacity of 14 Tb/s, while satisfying the requirements of the Class 1 laser safety standard.

Experimental demonstration of a “pin-like” low-divergence beam in a 1-Gbit/s OOK FSO link using a limited-size receiver aperture at various propagation distances

Nanzhe Hu, Huibin Zhou, Runzhou Zhang, Haoqian Song, Kai Pang, Kaiheng Zou, Hao Song, Xinzhou Su, Cong Liu, Brittany Lynn, Moshe Tur, and Alan E. Willner
Opt. Lett. 47(16) 4215-4218 (2022)

150 Gbit/s 1 km high-sensitivity FSO communication outfield demonstration based on a soliton microcomb

Shuaiwei Jia, Zhuang Xie, Wen Shao, Yang Wang, Yuanchen He, Dongquan Zhang, Peixuan Liao, Weiqiang Wang, Duorui Gao, Wei Wang, and Xiaoping Xie
Opt. Express 30(20) 35300-35310 (2022)

150 Gbps multi-wavelength FSO transmission with 25-GHz ITU-T grid in the mid-infrared region

Yulong Su, Jiacheng Meng, Tingting Wei, Zhuang Xie, Shuaiwei Jia, Wenlong Tian, Jiangfeng Zhu, and Wei Wang
Opt. Express 31(9) 15156-15169 (2023)

Performance analysis of FSO links employing a transmit and receive diversity-based operating system under Málaga turbulence channels with pointing errors

Akinchan Das, Banibrata Bag, Chayanika Bose, and Aniruddha Chandra
Opt. Continuum 1(2) 366-387 (2022)

Last mile access-based FSO and VLC systems

Atheer A. Sabri, Samir M. Hameed, and Wael A. H. Hadi
Appl. Opt. 62(31) 8402-8410 (2023)