What are Active Optical Cables?

HDMI Active Optical

Since we’ve started discussing our new 8K UHD HDMI Active Optical Cables, we’ve received some inquiries about active optical technology. The following answers some common questions.

What are Active Optical Cables?

Active optical cables (AOC) are cables with optoelectronic modules in the connector heads that convert electrical signals to light. Unlike passive copper cables, which send electronic signals directly down the internal copper wire, AOC involve additional signal conversions. In an active optical cable, electrical input is converted to photons via the combination of a specialized chipset or driver and laser(s). Photons are received at the other end of the cable and converted back to electrical impulses.

How is this powered? In our cables, the 5 volt output of HDMI ports provides the necessary voltage. While data is transferred over glass, the cables still contain copper wire conductors.

Are Active Optical Cables Directional?

cable head
HDMI AOC “Display” end

Yes. Because of the signal conversion activity at the cable heads, these cables are directional. Connector heads are marked “Source” and “Display.” Cables must be installed accordingly in order to function correctly.

Are HDMI Active Optical Cables the Only Type?

No. The earliest AOC were in data centers, with SFP/QSFP components. One of the earlier consumer-marketed AOCs we could find was a Luxtera DisplayPort AOC (shown at CES in 2008). There are now many active optical cables on the market, including the aforementioned DisplayPort AOC, HDMI AOC, USB AOC, and more.

Why Use a HDMI Active Optical Cable?

Active optical cables send data via optical fibers. This means much higher bandwidth capabilities than standard copper cables, as well as longer distances. Our 8K UHD HDMI Active Optical cables can send signal at 48 Gbps for up to 40 meters, which is well outside the capabilities of a standard copper HDMI cable.

HDMI Active Optical Cables can also reduce materials needed on installations, as AOC can (depending on your distance requirements) provide an alternative to running fiber cables to individual HDMI over fiber baluns.

Additionally, the optical fibers provide much greater resistance to electromagnetic interference, as well as lower latency. Lag is also reduced compared to standard copper cables, as signals are traveling at the speed of light.

Learn more about the capabilities of our Cleerline SSF™ HDMI Active Optical Cables.

Further Reading & References

What are Active Optical Cables?