Electrical data signals transmitted over copper are digital, meaning there is a ‘1’ or a ‘0’ that is transmitted at one end and received at the other end. Optical transmission is nearly identical. The electrical ‘1’ or ‘0’ is read by a chip inside our optical engine that tells the laser to output a brighter signal for a ‘1’ or a dimmer signal for a ‘0’ and a photodetector and receiver chip reverses the process and outputs the corresponding electrical ‘1’ or ‘0’.
Unlike copper cables, where higher bandwidths cause cross-talk problems with neighboring signals, optical signals are actually guided in the core of the fiber, so even laying a fiber right on top of another fiber will not cause any cross-talk, ground loops, or electromagnetic interference issues. Goodbye EMI problems!!
Inneos’ optical interconnects are even more unique in that they transmit multiple optical signals (channels) on the same fiber at the same time by using a different wavelength (color) for each channel.
For an optical interconnect solution using industry-standard fiber cables, using the correct fiber can make all the difference. If the optical subsystem is already chosen, look to see whether it is single-mode or multimode and be sure to use the fiber corresponding to the optical engine. Inneos optical subsystems use multimode fiber. Why? Because a multimode fiber has a larger core, the part of the fiber that transmits the signal, so it is more forgiving for field termination and multimode hardware is also generally less expensive than single-mode hardware. For distances longer than ~1km, single-mode optical subsystems and single-mode fiber are typically required.
There are four primary components to an optical fiber: the core, cladding, buffer, and outer jacket. The core is the area where the light is actually transmitted. In single-mode fiber with 9μm diameter core, only a single optical mode, or light wave behavior, is supported. In multimode fiber, the core is much larger at 50μm or 62.5μm, and multiple modes are supported. So how does the light stay in this core? The cladding layer provides a refractive index contrast that causes the light to reflect off the interface and propagate along the fiber core. If the fiber is run as a single strand, it is referred to as a “simplex” fiber cable, whereas if there are two strands of fiber run side-by-side, it is referred to as a “duplex” fiber cable. Applications that use special optics to perform multiplexing, such as the Inneos WaveStacker Optic, can simultaneously transmit and receive multiple high-speed signals on just one fiber, which makes the field termination even faster since it only needs to be performed once at each end.
Other terms that are used with multimode fiber include the classifications: OM5, OM4, OM3, OM2, and OM1. OM1 has a 62.5μm core whereas OM2, OM3, OM4, and OM5 have 50μm cores. The higher OM number corresponds to higher modal bandwidth, so generally OM3 or OM4 should be installed in new installations for lengths longer than 100m, with OM4 preferred over OM3, especially for 200m+ installation links. OM5 was specifically designed for wide-bandwidth wavelength-division multiplexing applications, so while it is great for the WaveStacker optic, it is generally more expensive than OM4.
The type of connector needed for the fiber cable is dependent on the connector that is on the mating hardware. Generally, it will be SC, LC, or maybe MTP/MTRJ. SC and LC connectors can both be readily terminated in the field with no-polish, no-epoxy termination kits from multiple vendors. SC connectors are slightly larger than LC connectors. MTP/MTRJ connectors have multiple fibers in them and cannot be terminated in the field because these fibers all must be carefully polished and aligned within the connector, which must be done in a factory with specialized equipment.
Yes, it is! Fiber cable is routinely pulled through the conduit during installation. Generally, a fiber cable includes a strength member to help with the pull strength and it can be pulled just like a typical category cable. The cable jacket material also comes in various options for riser or plenum requirements as well as the newer EU Construction Products Regulations for cables. These are standard options that are specified when ordering fiber cable, so the process is the same as any other category cable.
Fiber cable is tough enough for rugged applications too, including automotive, aerospace, and industrial environments. There is a wide range of fiber cable construction materials that are used for fiber cables that allow them to operate in ultra-wide temperature ranges applications, such are airplanes, automobiles, and factory assembly floors, high radiation environments such as satellites and nuclear power plants, and even high-pressure environments, such as down-hole sensor cables. Our team can help you spec the right fiber cable for your solution.
Field termination is actually pretty easy with field termination kits that are available from many different vendors, and there are also training videos available for many of them. With minimal training, terminating a fiber can be just as fast and easy, if not faster, than terminating a copper cable. Plus an additional benefit is that fiber cables don’t have the challenge of maintaining the critical shielding through the termination process that can lead to hard-to-detect signal integrity issues with copper cables.
What if I just want to run a pre-terminated fiber because I’m just not comfortable with doing fiber terminations yet? No problem! Pre-terminated fiber cables in almost any length and type and are available from many different vendors. Just make sure to put the dust cap on the fiber connector(s) while pulling the cable and don’t exceed the pull strength of the connector end.