Yellow, aqua, or orange? The meaning of fiber optic color standard
Fiber optic colors standards are crucial to anyone who works manipulating thousands of cables at day or doing a major installation.
The following definition of “standard” can be found in the ISO/IEC Guide 2:1996, definition 3.2:
‘A document established by consensus and approved by a recognized body that provides for common and repeated use, rules, guidelines or characteristics for activities or their results, aimed at the achievement of the optimum degree of order in a given context’.
In the realm of fiber optics and fiber optic cables, standards are what allow us to create uniform product specifications that make possible the confirmation of interoperability between different products from different manufacturers.
According to the Fiber Optics Association (FOA), these standards operate on two levels:
1.- Component level, covering specifications for cables and connectors, how to connect with other cables and the complete testing procedures.
2.- System level, cover protocols, signal bit rates, encoding of data, frequencies and amplitudes, packet length, timing, error correction and factors needed to ensure systems can talk to each other.
The TIA Technical Committee TR-42 (in the USA) and ISO JTC 1 (international) are the committees in charge of issuing standard reports for fiber optics and premises cabling.
Having as an end goal the production of a predictable minimum performance level in terms of cabling that other manufacturers can use as a guideline when designing and developing communications products.
Standards of: Single Mode Optical Fiber
Single mode optical fiber usually has an 8.3-micron diameter core and makes use of laser technology and light to send and receive data. A micron is a unit of measure equal to 1 millionth of a meter. So you can picture it: one strand of human hair has a diameter of more or less 100 microns.
Single mode fibers have the ability to carry information for miles without losing too many data which makes it ideal for companies that offer services such as cable and telephone providers.
Transmission distance is affected by chromatic dispersion because the core of single-mode fibers is much smaller than that of multimode fibers.
And it is also the reason why single-mode fiber can have longer transmission distance than multimode fiber.
High powered lasers operating within single mode optical fibers lend it its efficiency since they can readily transmit data at far greater distances the light used in their multimode counterparts.
If you need to handle large amounts of data with the least dispersion, single mode fiber might be your best choice. Just take into consideration that these fibers are noticeably more expensive than multimode ones since the technology used is a bit more sophisticated.
The following are the standards for single mode optic fiber as given by several international committees:
Standards for: Multi-mode Optical Fiber
Multimode optical fiber, as its very name indicates, allows the signal to travel through different pathways or modes that are placed inside of the cable’s core.
For these types of fibers, the transmission distance is largely affected by modal dispersion.
Due to the fact that the fibers in multimode cables have imperfections, the optical signals are not able to arrive at the same time causing a delay between the fastest traveling modes and the slowest ones, which in turn causes the dispersion and limits multimode fiber performance.
This type of fiber uses inexpensive LED (light emitting diode) light sources to transmit data.
The signal travels through a LED-based optical transmitter called a media converter, then down the glass in the fiber and bounces from wall to wall within the cable until it reaches its final destination at a rate of 10 or 100 Mb/sec but all that bouncing brings modal dispersion to the mix, diminishing the amount of data transmitted over a specific distance.
The demand for more data and faster reception of it has increased over the years making LED cables seem terribly slow and limited. This caused the creation of cables that use lasers to transmit data along with light, giving the world single mode optic fibers.
Multimode fibers can be found in 4 different presentations identified with the acronym OM which stands for optical multi-mode and varies according to performance criteria determined by ISO/IEC 11801 standards.
These presentations are OM1, OM2, OM3, and OM4.
The standards for multimode cables are as follows:
Fiber Optics Color Standards
Fiber optic cables are available in a wide range that varies according to use, length, diameter, etc.
Giving each one a specific color allows better and faster recognition of the cable in use and avoids issues due to bad connections or confusions.
Cable jacket colors make it faster and simpler to pinpoint which type of cable you are dealing with. Yellow, for instance, can identify a single mode cable (which it does), while orange identifies multimode cables and so on.
Here’s a guide to identify cables according to their jacket colors:
Inside each cable or in the inside of each tube in a loose tube cable, individual fibers will also be color coded for easy identification.
Fibers follow the convention created for telephone wires except fibers are identified individually, not in pairs.
For splicing, like color fibers are spliced to ensure continuity of color codes throughout a cable run.
For cables that have over 12 strands, the color code runs from 1 through 12 then repeats itself, identifying each 12-strand group in some other unique way such as adding a stripe to the second group (if it is a 24-strand cable) or some other specific mark to identify the new group
Each fiber number has a color assigned to it:
As for connectors:
They are also color coded for easy use and identification.
In the early day, it was simple: orange, black or gray was used to identify multimode cables while yellow was used for single-mode ones.
Currently, there is a wide array of cables to choose from, making it necessary to expand the color horizon.