FREESPACE OPTICAL UPGRADE

From the high power margin in the 2.1 km link demonstration, the researchers expect to be able to easily extend this distance.

The test range was limited to 2.1 kilometers because of obstructions in the high-density urban setting. Video transmission with few errors was demonstrated in different parts of the day, different seasons, and different weather conditions.

FREESPACE OPTICAL UPGRADE

The key upgrade they made to the system for it to work was at the receiver, where they used an OM4 multimode fiber rather than single-mode fiber, resulting in a 10-decibel improvement to the signal coupling efficiency. The group used standard single-mode optical fibers on the transmitter side of the system to launch 16 ultrahigh-definition video streams as free-space optical signals. 'These factors lead to serious attenuation of optical signals, resulting in very low received power.' 'In urban, due to the influence of factories, automobile exhaust, and other factors, there are more particles, molecules, dust, and so on in the atmospheric channel than in other places, such as mountains,' said Zhan. Zhan will report the results of their demonstration during a session at the Optical Fiber Communication Conference and Exhibition (OFC), being held virtually from 06 - 11 June 2021. Interest in FSO communications is growing again with improved technologies and the drive for higher bandwidth services where wireline solutions are difficult.Īt the forefront of these new developments, Yueying Zhan and her team of researchers achieved the real-time FSO transmission of 1,000 seconds of an ultrahigh-definition video stream between two buildings in Beijing. Twenty years ago, there were nascent activities in FSO communications for urban settings, which faded because of technical challenges and competing RF wireless and wireline solutions.

Previous work on terrestrial FSO transmissions focused on either indoors or areas with little atmospheric effects, like between two mountain peaks. Free-space Optical Networks Improvements Enable Wireless Transmission in Urban Settings

Freespace optical