Lab-Based “Li-Fi” Link Exceeds 7 Gb/s Using Blue Micro LED

Arun Bhatia
2 min readOct 13, 2020
The single 10-µm GaN-based micro-LED is the blue-light source for the data stream. (Source: CEA-Leti)

Here’s more good news on “LiFi” innovation!

I reported about the “LiFi” progress recently in my last “TECH LIFE” newsletter issue-3 on 13th Sep 2020. You can take a look at it here in case you missed it. We all have been eagerly awaiting the progress and further commercialization of this promising technology. So here is some more welcome good news on the same subject.

Taking advantage of a blue GaN micro-LED, researchers succeeded in operating a free-space optical link at over 7 Gb/s, possibly functioning as a precursor of a super-speed “Li-Fi” type link.

As an optically based complement to RF-based Wi-Fi, “Li-Fi” (light fidelity) offers distinct attributes including extremely high throughout over limited distances and immunity from EMI/RFI. One other characteristic of an optical link: Its line-of-sight path provides outstanding immunity to eavesdropping and hacking, but also limits user mobility.

Adoption of Li-Fi in the marketplace has been very limited thus far. However, there’s an industry association that provides standards and support, and you can refer to the links at the end of this post.

Researchers, of course, see pushing the envelope of optical-based data links as an area of great interest.

In addition to the micro-LED experiment shown in the picture, the CEA team also developed an advanced multi-carrier modulation scheme combined with digital signal processing to achieve their results. This high spectrum-efficiency waveform was transmitted by the single LED, received on a high-speed photodetector, and demodulated using a direct sampling oscilloscope.

My post is based on extracts and references from Bill Schweber’s post on Sep 22nd, 2020 in the “Electronic Design” magazine.

LiFi Resources

http://lightcommunications.org/
https://standards.ieee.org/standard/802_15_7-2018.html
https://www.lifitn.com/im-new
https://en.wikipedia.org/wiki/Li-Fi#Standards

https://www.arunbhatiaconsulting.com/

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