Tips N Articles: Optic fiber

Learn more about Fiber Optic
Third-generation digital fiber optic products offer a unique advantage compared to older analog transmission products and copper-based systems: Performance consistency. Regardless of the fiber cable length used, the base band video and audio performance will always be high fidelity and deliver consistent performance throughout the system.

Point-to-multipoint distribution of AV signals can be easily achieved using digital fiber technology. Topologies can be as complex or as simple as necessary. Because the baseband AV signals are never processed during distribution, they don't undergo any of the distortions during transmission that are common in traditional copper-based distribution technologies.

A common misconception of fiber is that it's fragile, although normal PVC-jacketed fiber is actually very rugged. It has a relatively tight bend radius, which is better than Cat6, and can be subjected to normal abuse in a typical staging installation. Because fiber optic cable uses Kevlar as part of its construction, it can withstand a lot of abuse without breaking the internal glass fiber.

It's often necessary to convert from multimode to single-mode fiber during a transmission. This can easily be done if the transmission uses digital signaling. A one-in, one-out, active optical distribution amplifier can be configured to perform the conversion without any degradation to the baseband signals being transmitted.

If you have an existing fiber optic installation that needs to be upgraded, consider replacing all of the existing transmitters and receivers with new digital multiplexers. You'll not only improve the quality of your transmissions with state-of-the-art products, but will send more signals over fewer fibers, freeing up existing fibers for future applications.

When considering the expense of using fiber compared to coax or copper for AV distribution, look at the cost of all the elements of installation, including the cost of cable, installation labor, conduit, cable routing, setup, and support time. When you factor in all these hidden but real costs, you'll see that the economic and technical benefits of fiber go beyond long distance signal transmission.

In determining the maximum distance that can be communicated over fiber cable, the optical loss budget, which the hardware manufacturer specifies in dB, must not be exceeded. In almost all AV installations, most of the optical loss comes from connectors, splices, patch cords, and panels, rather than from the actual fiber. Keep this in mind when designing your system.

A unique characteristic of fiber optic cable transmission is its complete immunity to picking up stray signals. Because there is no metallic content in fiber cable, it doesn't act like an antenna. Therefore, signals from radio transmitters, electric motors, walkie-talkies, and other similar devices won't interfere with video, audio, and data being transmitted through the fiber.

ave you ever wished that you could simply connect two boxes in the field and have an instant connection? With digital fiber optic transmission systems, you'll get your wish. No adjustments are required to compensate for signal levels or varying transmission distances. Regardless of fiber length, digital systems deliver crystal clear video and audio.

One of the greatest enemies of fiber optic communications is something that often can't be seen. Minute particles of dirt and dust located on fiber connectors can act like a window shade blocking light. Before performing a termination, always clean the tip of a fiber connector with alcohol and a lint-free wipe.

If you're installing fiber cable in a permanent installation, it pays to install single-mode fiber instead of multimode fiber. Why? The higher bandwidth and signal-carrying capacity of single-mode fiber is something you'll certainly want to use in the future. Multimode fiber may be adequate for today's needs, but single-mode fiber will make the cost worthwhile over time.

Did you know that fiber optic cable is the lowest cost cable type for AV applications? It's less expensive than CAT-5, 5e, 6 and even the new no-skew UTP, and is significantly less expensive than coax. A single fiber strand can carry as much information as a multiple high-resolution coax bundle, and now fiber is as easy to terminate as coax.

Are you considering fiber for a future installation but nervous about performing terminations in the field? Today's fiber is as easy to terminate as BNCs on COAX. New field termination kits completely eliminate the need for grinding, polishing and the use of epoxy. And an easy-to-use jig guarantees precision alignment every time. The 2003 Fiber-Ed.com World Tour may be coming your way soon! To learn all about digital fiber optics for the pro AV market, including a lesson on how to terminate fiber, click here.

One of the great advantages of fiber, compared to copper transmission, is the ability to communicate video, audio and data bi-directionally over one fiber. One technique called Wave Division Multiplexing (WDM) uses one wavelength of light to send the signal in one direction and a different wavelength for the reverse path. No, the lights don't interfere with each other inside the fiber and they are easily combined and separated at each end.

Exploiting the capacity of fiber is done using a technique called Digital Multiplexing. Here, we digitize many video, audio and/or data signals and combine them into one high-speed data stream. This multiplexed stream is then sent on one wavelength over the fiber cable.
At the optical receiver, the process is reversed and the original signals are recovered for the user. Enormous capacity is achieved compared to alternate copper-based technologies.

The link budget is the one parameter in fiber optic system design that is the most important, but often overlooked. Measured in dB, it's the maximum amount of optical signal loss that can be tolerated between the transmitter and the receiver and is specified by the equipment manufacturer. In AV systems, it's not the fiber cable that is the biggest contributor to this loss. Rather, it's all the mechanical connections and the unseen enemy: dirt and dust. Keep your connections clean!

What's the difference between single-mode and multimode fiber? Single-mode fiber now costs no more than multimode fiber and offers many advantages, including much greater signal capacity and longer transmission distance. Fiber optic products designed for use with single-mode fiber cost more due to the optics required to pass light through the thinner fiber core. However, the use of single-mode fiber provides for more utilization over time in permanent installations.

Digital fiber optics provide great flexibility when designing signal distribution topologies for point-to-multipoint pro AV systems. Daisy-chaining and use of digital optical distribution amplifiers eliminate the need for costly home-runs to each endpoint. Plus, all digital signaling guarantees that uniform quality will be provided to each display, regardless of its distance from the source.

Lightweight, easy to handle, flexible and thin, the unobtrusive nature of fiber makes it ideal for staging applications. It can be tucked almost anywhere, making it practically invisible to audiences. However, fiber isn't delicate. Whether bent, pulled or crushed, fiber can stand up to the most rugged wear and tear any staging environment can offer.

Lower cost of Plenum-rated fiber compared to plenum-rated copper: Fire regulations require the use of plenum-rated cable. That's usually a 100 percent premium cost over standard coax and CAT-5 cables. Not so with fiber. Plenum-rated fiber cable only carries a 10% premium or less over standard PVC cable. That's a real savings!

Did you know that one of the key benefits of using digital fiber optics for signal distribution is guaranteed signal consistency over the entire transmission path? Over short or long distances, video, audio and data signals arrive at their destination in the same pristine quality as they originated. Digital fiber optic technology eliminates noise, crosstalk and non-linear distortions, and best of all; it does so for the same price or less than analog systems of yesterday.

One of the unique properties of fiber optic transmission is its security. Fiber does not radiate any of the signals it communicates the way copper based transmissions do. It cannot be proximity monitored nor cause interference to any adjacent electronic equipment. Sensitive
military and corporate applications are now widely deploying fiber for even the shortest transmission distances.

Low Cost of Fiber: Did you know fiber optic cable is the lowest cost cable type for A/V? It's less expensive than CAT-5, 5e, 6 and even the new "no-skew" UTP and significantly less expensive than coax. A single fiber strand can carry as much information as a multiple hi-res coax bundle and now fiber is as easy to terminate as coax.