Optical fiber cables for professional audio / video applications

Optical fiber has played a key role in our industry for years. Operational reliability, performance (extremely high transmission bandwidth), and ease of installation are the defining traits that make it the winning choice for professionals working in pro audio / video. More and more integrators, rental companies, and service providers are selecting optical fiber cables for their projects and productions. We’ll begin with an overview of the core concepts and then focus on the essential characteristics that make optical fiber the strategic choice for interconnecting AV equipment.

Optical fiber is a slender cable made from ultra-pure glass (silica) or polymer (plastic) that guides light inside it. Unlike electrical cables—whether signal or power—only optical signals propagate in fiber. Because light is an electromagnetic wave with a frequency in the visible spectrum (or near infrared), optical fiber essentially acts as a waveguide that carries the signal along a defined path.

We won’t go into full theory here: in short, light pulses representing digital information (0 / 1) travel through a very thin glass / plastic filament (the core) by “bouncing” within it thanks to total internal reflection. The core is surrounded by a solid reflective layer (cladding) and a protective jacket (coating).

For the light pulses to reflect inside the core, they must be injected into the fiber within a specific acceptance angle.

Optical fibers can operate at different wavelengths; in practice three are commonly used, depending on whether the fiber is single-mode or multimode. Thanks to wavelength division multiplexing (WDM), dozens or even hundreds of wavelengths can be carried simultaneously over the same fiber.

Single-mode and multimode fibers: what’s the difference?

Based on how they transmit light, fibers are categorized as single-mode (only one light path traverses the core) or multimode (multiple light paths).

Single-mode fibers, with a 9 µm core, are ideal for long-distance transmission (up to ~100 km), whereas multimode fibers, with core diameters between 50 and 62.5 µm, suit shorter runs up to ~2 km. Multimode offers lower bandwidth and higher dispersion but generally at a lower cost.

Both types are used in pro AV. Single-mode is preferred for long runs (university campuses, sports venues), broadcast links, and large-scale live infrastructures. Multimode fits much shorter distances typical of studios, theaters, conference rooms, and device-to-device links in indoor environments.

Professional Agora network switches such as the Ghost MK2, among others support opticalCON or SmartBeam fiber ports that can be configured in DUAL or QUAD mode. While the switches themselves don’t inherently distinguish single-mode vs multimode, the hardware allows the use of transceivers compatible with both SMF and MMF, depending on the chosen configuration.

Why choose optical fibers over copper cables?

The widespread adoption of optical fiber over copper is primarily due to:

• Much lower attenuation, enabling (even uncompressed) signals to travel far longer distances without necessarily using repeaters

• Immunity to electromagnetic interference and crosstalk

• Very wide bandwidth and extremely high data rates (100 Gbps and beyond, even into Tbps)

• Excellent resistance to many chemical agents

• Low weight and small footprint

• Flexibility (a major advantage during installation)

• Long service life, with the caveat that transmit/receive devices may need replacement over time and minimal maintenance is required (connector cleaning, protection from the elements, etc.)

In AV applications (seen below), devices are often used to convert between electrical and optical domains: fiber AV extenders, media converters, SDI fiber converters, and so on.

Two examples of HDMI optical fiber extenders distributed by Audio Effetti: Pixelhue EP4T-S and Beetek Technology M1-H20-Lite

For bidirectional 12G-SDI to fiber conversion, devices like the Blackmagic Design Mini Converter – Optical Fiber 12G can be used.

Application areas for optical fiber cables in professional AV

Now that we’ve reviewed the key characteristics, here are typical application domains:

High-resolution video transmission over long distances

• Live events (concerts), stadiums, theaters, trade shows, multi-building installs

• Benefits: uncompressed 4K / 8K over tens of kilometers with no degradation, zero latency, and no quality loss

Environments with strong electromagnetic interference

• TV studios and broadcast control rooms, convention centers, control centers

• Benefits: total immunity to EMI / RFI; no risk of hums or ground loops

Digital signage, AV content distribution

• Shopping malls, airports, train stations, university campuses

• Benefits: star, daisy-chain, or point-to-point topologies for maximum flexibility; no signal loss when feeding one AV source to multiple displays

Fixed installations

• Conference rooms, museum installs

• Benefits: lightweight, thin cables that are easy to install

Broadcasting and video production

• OB vans, production studios, TV broadcasts

• Benefits: zero-frame-delay transmission for perfect sync; compatibility with control systems and embedded audio

Construction aspects

Optical fiber cables for pro AV differ from telecom variants not only in performance requirements, as noted, but also in their physical construction, termination types, and usage patterns.

While manufacturing R&D aims for low attenuation, limited dispersion, and tight dimensional tolerances, leading manufacturers such as Beetek also implement a range of measures to withstand the harsh conditions typical of touring.

Beetek fiber cables are armored for outdoor use and available with multiple conductors. Tailored for demanding environments where rapid cabling is required, they feature a hybrid reinforced outer jacket combining metallic elements and fibers. These layers provide mechanical protection against physical damage, moisture, and other environmental factors suited to the harshest conditions. Connectors are protected by dust- and moisture-proof caps.

Speaking of connectors, the options are truly wide-ranging, as illustrated in the following image:

 

The most commonly used in our sector are LC (Lucent Connector), SC (Square Connector), ST (Straight Tip), and MTP/MPO. There are also Neutrik opticalCON connectors, offering powerCON-grade ruggedness and reliability while carrying signals over optical fiber.

 

Connectors are interfaced to equipment via SFP (Small Form-factor Pluggable) modules—compact, hot-swappable optical transceivers used to interconnect devices.

Supply formats vary by application:

Bulk spools

• Lengths from 50 to 1000 m, to be terminated on site
• Ideal for installers and AV integrators when termination type is not known in advance

Pre-terminated (ready to use) – see Beetek products

• Cables shipped with connectors fitted, tested, and certified
• Fixed lengths, typically 5, 10, 20, 50, 100, 200, 300 m, etc.
• Ideal for rental, live events, and rapid deployments

Hybrid (fiber + copper)

• Combined cables for AV transport (fiber) plus power / control (copper)
• Used with PTZ cameras, mobile AV systems, etc.

 

In summary, optical fiber cables are today’s most advanced technology standard for professional audio / video applications. Their ability to carry ultra-high-resolution signals over long distances, immunity to interference, and installation flexibility make them essential in every context—from live touring to broadcast, from fixed installations to digital signage. Audio Effetti stands beside professionals with certified products, technical support, and tailor-made solutions for every requirement.

Want to learn more?

Email us at international@audioeffetti.it