A Complete Guide to Fibre Optic Cables

Fibre optic cables are the backbone of modern communication networks, enabling lightning-fast data transfer and high-bandwidth connectivity. This comprehensive guide explores the workings, applications, and myriad benefits of fibre optic cables.

Fibre optic technology is a highly effective communication system that uses cables to transmit data as pulses of light. It is reliable, versatile, and widely used in many applications and industries.

Fibre optic cables consist of one or more thin strands of transparent glass or plastic, each slightly wider than a human hair. These strands, known as optical fibres, are surrounded by a cladding layer, also made of glass or plastic, but with a different density. This density difference is crucial for guiding light along the fibre.

A protective sheath, comprising several layers of insulated casing, encases the cladded fibres. This typically includes a buffer tube for added protection and an outer jacket to safeguard the entire multi-stranded cable.

Fibre optic cables are an advanced type of network cable that offer significantly improved performance compared to traditional metal conductor cables. It provides superior bandwidth and data-carrying capacity, making it ideal for high-speed communication networks and data-intensive applications.

The optical fibres of fibre optic cables are primarily made of thin glass or plastic strands. They are incredibly pure and transparent, allowing light to travel through them with minimal loss.

Surrounding the fibres is a cladding layer, typically made of a different type of glass or plastic, which helps to confine the light within the core and guide it along the length of the cable.

To protect these delicate fibres, several layers of protective materials are added. These often include a buffer tube made of a flexible material like PVC or polyethylene, which provides cushioning and absorbs shocks.

Additionally, an outer jacket made of a durable material like polyurethane or polyethylene encases the entire cable, providing protection against abrasion, moisture, and other environmental factors.

To understand how fibre optic cables work and how data is transmitted through them, it is important to recognise the key components involved in their construction and operation. While the glass or plastic strands are central to the system, several other components play a vital role in ensuring successful data transfer.

Firstly, a source of light is needed to transmit light pulses that carry information along the fibre optic cable. This light source is usually a tiny laser or an LED diode, which converts electrical signals from the transmitter into light pulses. These light pulses are then launched into the core of the fibre optic cable.

Next, the core of the fibre optic cable must be surrounded by a cladding layer, which has a lower refractive index than the core. This refractive difference means the incoming light pulses are bent at different angles as they travel the length of the cable, keeping the light pulses confined within the core.

They move along the cable run's full length, bouncing in a zig-zag pattern to navigate bends. At various points, they might be converted into electrical signals before turning back into light pulses again. Additional components called repeaters are used to maintain signal strength for longer cable runs.

After travelling at approximately 70% of the speed of light for the majority of the journey, the light signals are interpreted as communications or data signals when they arrive at their destination. Receiving equipment is used to convert them to the desired output.

A Visual Representation for How Fibre Optic Cables Work

The optical fibre diagram below shows the basic principle of the technology and how it works.

Light enters at one end of the cable and travels through the highly refractive core, bouncing off the cladding which has a low refractive index.

Once a beam reaches the end, it is dispersed at an approximately 60° angle and emitted to the target.

Fibre optic cables power various applications across numerous sectors in New Zealand. They are commonly found in telecommunications infrastructure, providing the backbone for high-speed internet and broadband services, as well as carrying data for phone lines and other communication networks.

Beyond telecommunications, fibre optic cables also see applications across homes, healthcare, and industrial settings.

Medical Field

In the medical field, fibre optic cables are indispensable for a range of applications. They are used in inspection cameras for endoscopes to provide minimally invasive internal examinations and surgical procedures.

Additionally, they enable high-resolution imaging in medical equipment, such as microscopes and scanners, aiding in diagnosis and treatment.

Mechanical Inspections

Fibre optic cables play a crucial role in mechanical inspections across various New Zealand industries. For example, they are used in borescopes to inspect the interior of machinery and equipment, such as engines, pipelines, and aircraft structures, allowing for the detection of defects or damage without disassembly.

They also act as sensors for monitoring and controlling the flow of various sorts of electrical currents, sounds and chemicals.

Automotive Industry

Fibre optic cables are increasingly used in the automotive industry to provide efficient and reliable data transmission for advanced driver-assistance systems (ADAS), such as lane departure warning and adaptive cruise control.

Additionally, they are used for in-car entertainment systems, providing high-quality audio and video connections.

Optical Fibre for Internet and Computer Networking

Fibre optic internet cable is rapidly gaining popularity in New Zealand due to the higher speeds and bandwidth it can provide compared to standard ethernet or Wi-Fi signals delivered via traditional copper-based connections. This means that fibre networking is a far better choice for data-intensive tasks and where high-speed connectivity is required, such as streaming and gaming.

Fibre Optic Cables for Lighting

LED lighting with fibre optic cables is also a common application of fibre optic technology in residential and commercial environments. Fibre optics can transmit data in a clean and versatile manner across a wide spectrum of colours and patterns. This means that it is widely used in ambient lighting applications, accent lights, and feature lamps.

Compared to traditional incandescent or fluorescent lighting, fibre optic LED lighting consumes significantly less energy, making it an environmentally friendly and cost-effective choice. Moreover, they are safe to use in various environments as they do not carry electrical current and are highly resistant to wear, damage and degradation.

Fibre optic cabling offers several key advantages compared to traditional copper conductor cables, making them a superior choice for many modern uses.

Longer Transmission Distance

Because of their low signal power loss rate, fibre optic cables are able to transmit data over much longer distances than older types of cabling. This is because light signals travelling through optical fibres experience less attenuation than electrical signals in copper wires.

With the right combination of network setup, cable materials, and transmission wavelength, some fibre optic cables can effectively carry signals over hundreds of kilometres. In contrast, standard copper cables have a practical limit of around 100 meters (328 feet) for reliable data transmission.

Higher Bandwidth for Data Transfer

Fibre optic cables offer significantly higher bandwidth compared to copper cables. This means they can carry a much larger volume of data at higher speeds. The higher bandwidth of fibre optic cables is due to their ability to transmit data using light, which has a much higher frequency than electrical signals used in copper cables.

This feature allows for greater capacity for carrying information, making fibre optic cables ideal for data-intensive applications.

Faster Transmission Speed

Fibre optic cables offer a significant speed advantage compared to other data transfer modes because they use light pulses to transmit information. As light travels at a much faster speed than electrical copper cables, fibre optic cables can achieve significantly higher data transfer rates.

These rates exceed the capabilities of even high-grade copper ethernet cables like Cat5 and Cat6, making fibre optics the preferred choice for applications where speed is critical, such as high-frequency trading, data centres, and telecommunications networks.

Less Interference

Fibre optic cables are inherently less susceptible to electromagnetic interference (EMI) and crosstalk compared to copper cables. This is because fibre optic cables transmit data using light, which is not affected by electromagnetic fields.

In contrast, copper cables can pick up interference from nearby electrical equipment or other cables, leading to signal degradation and data corruption. The superior noise immunity of fibre optic cables makes them ideal for applications where signal integrity is crucial, such as industrial automation, medical equipment, and sensitive scientific instruments.

Better Reliability and Safety

Although fibre optic cables are usually a lot lighter and thinner, they are also sturdier. This means that they can withstand far greater pulling forces, reducing the risk of breakage or damage across long runs.

Furthermore, fibre optic cables are less susceptible to environmental factors like moisture, poor weather, or extreme temperatures, making them a durable choice for various applications in New Zealand. Additionally, as glass fibres do not carry current, they eliminate the risk of electrical shock and fire hazards even when aged or damaged.

Long Term Cost Efficiency

While some fibre optic cables may have a higher initial cost compared to copper cables, their exceptional durability, longevity, and lower maintenance requirements often result in a lower total cost of ownership over time.

Additionally, advancements in fibre optic technology continue to drive down the cost of components and installation, making fibre optics an increasingly cost-competitive solution for various uses.

Optical fibre cabling has numerous key classifications and characteristics. These directly impact its efficiency regarding line speed, signal strength, and bandwidth.

Below is a number of factors which could influence optical cable's overall performance.

Fibre optic cable connectors are essential components that provide a secure and reliable connection between fibre optic cables and various devices or equipment. Several different connector types are available and it is important to choose the appropriate one for successful fibre optic connection. This choice will depend on factors such as the fibre optic cable type, application requirements, and the specific equipment being used.

Some of the most common types of fibre optic cable connectors include: