Optical fibre is rising in both telecommunication and data communication due to its unsurpassed advantages: faster speed with less attenuation, less impervious to electromagnetic interference (EMI), smaller size and greater information carrying capacity. The unceasing bandwidth needs, on the other hand, are also yielding significant growth in optical fibre demands. Let’s take a review of common fibre optic cable types, explore the advantages and disadvantages of optical fibre, and learn tips on selecting fibre optic cable.
What Is Optical Fibre?
Optical fibre uses light pulses instead of electrical pulses to transmit information, thus delivering hundreds of times higher bandwidth than traditional electrical systems. Fibre optic cable can be protected by sheathing and armour to make it resistant to harsh environmental conditions. Hence it is widely adopted in commercial business, governments, military and many other industries for voice, video and data transmission.
How Optical Fibre Works
The working principle of optical fibre is based on the phenomenon of total internal reflection of light. When light enters the core with a higher refractive index and strikes the boundary with the cladding, which has a lower refractive index, at an angle greater than the critical angle, it is reflected entirely within the core rather than passing through the boundary. This total internal reflection allows the light to propagate through the fibre’s core, enabling efficient transmission of light signals even through bends and curves.
Common Fibre Optic Cable Types
Generally, there are three types of fibre optic cables: the two glass optical fibre—single mode fibre optic cable and multimode optical fibre, as well as plastic optical fibre (POF).
Single Mode Fibre Optic Cable
The “mode” in fibre optic cable refers to the path in which light travels. Single mode fibre has a smaller core diameter of 9 microns (8.3 microns to be exact) and only allows a single wavelength and pathway for light to travel, which greatly decreases light reflections and lowers attenuation. Slightly more expensive than its multimode counterparts, single mode fibre optic cable is often used in network connections over long lengths.
Multimode Fibre Optic Cable
Multimode optical fibre has a larger core diameter than that of single mode fibre optic cable, which allows multiple pathways and several wavelengths of light to be transmitted. Multimode optical fibre is available in two sizes, 50 microns and 62.5 microns. It is commonly used for short distances, including patch cable applications such as fibre to the desktop or patch panel to equipment, data and audio/video applications in LANs. According to the fibre refractive index distribution, multimode fibre can be divided into two types: Step-Index Multimode fibre vs Graded-Index Multimode fibre.
Plastic Optical Fibre (POF)
POF is a large core step-index optical fibre with a typical diameter of 1 mm. The large size enables it to easily couple lots of light from sources and connectors that do not need to be high precision. So typical connector costs are 10-20% as much as for glass fibres and termination is simple. Being plastic, it is more durable and can be installed in minutes with minimal tools and training. For applications do not require high bandwidth over great distances, POF is more competitive, making it a viable option for desktop LAN connections and low speed short links.
FS offers single-mode and multi-mode patch cables, covering a variety of types including OS2, OM1, OM2, OM3, OM4, and OM5, with customisation services available. Additionally, various specialised patch cables are available for purchase, such as armoured, industrial, and high-density options. All FS patch cables undergo rigorous testing to ensure you receive a high-quality product.
Advantages and Disadvantages of Optical Fibre
Though optical fibre has speed and bandwidth advantages over copper cable, it also contains some drawbacks. Here are the advantages and disadvantages of optical fibre cable.
Advantages of Optical Fibre
Greater bandwidth & faster speed—Optical fibre cable supports extremely high bandwidth and speed. The large amount of information that can be transmitted per unit of optical fibre cable is its most significant advantage.
Cheap—Long, continuous miles of optical fibre cable can be made cheaper than equivalent lengths of copper wire. With numerous vendors swarm to compete for the market share, optical cable price would sure to drop.
Thinner and light-weighted—Optical fibre is thinner, and can be drawn to smaller diameters than copper wire. They are of smaller size and light weight than a comparable copper wire cable, offering a better fit for places where space is a concern.
Higher carrying capacity—Because optical fibres are much thinner than copper wires, more fibres can be bundled into a given-diameter cable. This allows more phone lines to go over the same cable or more channels to come through the cable into your cable TV box.
Less signal degradation— The loss of signal in optical fibre is less than that in copper wire.
Light signals—Unlike electrical signals transmitted in copper wires, light signals from one fibre do not interfere with those of other fibres in the same fibre cable. This means clearer phone conversations or TV reception.
Long lifespan—Optical fibres usually have a longer life cycle for over 100 years.
Disadvantages of Optical Fibre
Low power—Light emitting sources are limited to low power. Although high power emitters are available to improve power supply, it would add extra cost.
Fragility—Optical fibre is rather fragile and more vulnerable to damage compared to copper wires. You’d better not to twist or bend fibre optic cables too tightly.
Distance — The distance between the transmitter and receiver should be kept short or repeaters are needed to boost the signal.
How to Select the Right Optical Fibre Cable?
Optical fibre cable has gained much momentum in communication networks, and there emerges a dazzling array of vendors competing to manufacture and supply fibre optic cables. When selecting optical fibre, you’d better start with a reliable vendor and then consider the selection criteria. Here’s a guide to clarify some of the confusions about choosing fibre optic cable.
Check Manufacturer Qualification
The major optical cable manufacturers should be granted ISO9001 quality system certification, ISO4001 international environment system certification, the ROHS, the relevant national and international institutions certification such as the Ministry of Information Industry, UL certification and etc.
Fibre Mode: Single Mode or Multimode
As illustrated above, single mode fibre is often used for long distances while multimode optical fibre is commonly used for short range. Moreover, the system cost and installation cost change with different fibre modes. You can refer to Single Mode vs Multimode fibre: What’s the Difference? and then decide which fibre mode you need.
Optical Cable Jackets: OFNR, OFNP, or LSZH
The standard jacket type of optical cable is OFNR, which stands for “Optical fibre Non-conductive Riser”. Besides, optical fibres are also available with OFNP, or plenum jackets, which are suitable for use in plenum environments such as drop-ceilings or raised floors. Another jacket option is LSZH. Short for “Low Smoke Zero Halogen”, it is made from special compounds which give off very little smoke and no toxic when put on fire. So always refer to the local fire code authority to clarify the installation requirement before choosing the jacket type.
Optical Fibre Internal Construction: Tight Pack or Breakout or Assembly or Loose Tube
Tight pack cables are also known as distribution style cables, features that all buffered fibres under a single jacket with strength members for Enclosure to Enclosure and Conduit under Grade installations. Breakout fibre cable or fan out cable is applicable for Device to Device applications with tough and durable advantages. Assembly or zip cord construction is often used for making optic patch cables and short breakout runs. While loose tube construction is a Telco standard used in the telecommunications industry.
Indoor vs. Outdoor
The choice greatly depends on your application. The major difference between indoor and outdoor fibre cable is water blocking feature. Outdoor cables are designed to protect the fibres from years of exposure to moisture. However, nowadays there have been cables with both dry water-blocked outdoor features and indoor designs. For example, in a campus environment, you can get cables with two jackets: an outer PE jacket that withstands moisture and an inner PVC jacket that is UL-rated for fire retardancy.
Fibre Count
Both indoor and outdoor fibre cable have a vast option of fibre count ranging from 4-144 fibres. If your fibre demand exceeds this range, you can custom the fibre count for indoor or outdoor optical cable. Unless you are making fibre patch cords or hooking up a simple link with two fibres, it is highly recommended to get some spare fibres.
Conclusion
Optical fibre provides a fast, constant and stable Internet connection that allows a lot of data to be transmitted over incredible distances. As data demands become enormous, fibre optic cabling is the sure way to go for network flexibility and stability.
FS offers a wide range of network devices and can also customise products to meet specific user needs. Our expert team can design tailored solutions for building cost-effective and high-quality networks. Visit the FS website now to learn more about our products and solutions. Our professional technicians are always available to answer any questions you may have.