Optical Fibre

Understanding Optical Fibre and Its Applications

Optical fibre is a thin, flexible strand of glass or plastic that transmits light signals over long distances with minimal loss of signal quality. This technology is widely used in telecommunications to enable high-speed data transmission, including internet, telephone, and television services.

Key Features of Optical Fibre:

High Bandwidth

Optical fibres can carry large amounts of data at very high speeds, making them ideal for internet and communication networks.

Low Signal Loss

Light signals travel through optical fibres with minimal attenuation, allowing for long-distance transmission without significant loss of quality.

Immunity to Electromagnetic Interference

Unlike metal wires, optical fibres are not affected by electromagnetic interference, ensuring a more stable and reliable connection.

Flexibility and Durability

Optical fibres are flexible and can be bent without breaking, making them suitable for various installation environments.

Applications:

Telecommunications: Used for high-speed internet, telephone, and television services.

 

Medical: Employed in endoscopy and other medical imaging techniques.

 

Industrial: Used in sensors and for data transmission in harsh environments.

 

Military and Aerospace: Utilised for secure and reliable communication systems.

How It Works

Optical fibre works on the principle of total internal reflection. Here’s a breakdown of how it functions:

Core and Cladding

An optical fibre consists of a core (the central part) and cladding (the outer layer). The core is made of glass or plastic with a high refractive index, while the cladding has a lower refractive index.

Light Transmission

Light signals, usually from a laser or LED, are sent into the core of the fibre. Because the core has a higher refractive index than the cladding, the light is confined within the core.

Total Internal Reflection

When light hits the boundary between the core and cladding at a shallow angle, it reflects back into the core instead of passing through the cladding. This process is called total internal reflection and allows the light to travel long distances with minimal loss.

Signal Transmission

The light signals carry data encoded in various forms, such as digital pulses. These signals can travel through the fibre at very high speeds, making optical fibres ideal for high-bandwidth applications like internet and telecommunications.

Repeaters and Amplifiers

For very long distances, repeaters or amplifiers are used to boost the signal strength and ensure it reaches its destination without significant degradation.

Decoding

At the receiving end, the light signals are converted back into electrical signals by a photodetector, which then decodes the data for use in various applications.

This efficient method of transmitting data makes optical fibre a cornerstone of modern communication networks, providing fast, reliable, and high-capacity connections.

 

Given the high demand for optical fibres and limited space for installation, cables typically contain multiple fibres. To fit more fibres into a single duct, it’s crucial to minimise the diameter of both the fibres and the cables.  Each fibre within the cable is colour-coded for easy identification at both ends, similar to the system used for electrical wires.

 

Higher fibre density offers several advantages, including reduced costs for packaging and transportation, quicker installations, and a smaller carbon footprint.  However, it’s vital to ensure that reducing size and increasing density does not compromise fibre performance. Compatibility with existing networks must also be maintained, allowing thin fibres to connect seamlessly with standard-diameter fibres.

Innovations by Prysmian

Prysmian has developed advanced optical fibre cables such as SiroccoHD and Sirocco Extreme through a series of innovative approaches and technological advancements:

 

  1. Bend-Optimised Fibres: Prysmian utilises BendBright XS single-mode fibres, which are optimised to maintain high performance even when bent. This is essential for installations in tight and complex environments.

     

  2. Colour Coded 180µm fibre optic: Prysmian is currently the only manufacturer that produces a reduced diameter 180µm optical fibre that is already colour coded. This innovation helps in identifying fibres easily and efficiently, which is crucial for installation and maintenance.

     

  3. Ultra-Thin Design: The SiroccoHD and Sirocco Extreme cables feature ultra-thin fibres, initially 200μm and later reduced to 180μm. This reduction in diameter allows for a higher fibre count within a compact cable, enhancing the capacity without increasing the overall size.

     

  4. High Fibre Density: These cables are designed to support high-density access networks, FTTx (Fibre to the x), and 5G infrastructures. The high fibre count within a small diameter makes them ideal for modern, data-intensive applications.

     

  5. Air-Blown Installation: The cables are engineered for air-blown installation, a method that uses compressed air to blow the cables through ducts. This technique simplifies the installation process, reduces the need for specialised labour, and minimises disruption.

     

  6. Environmental Impact: Prysmian focuses on reducing the environmental footprint by using fewer raw materials and creating cables with a smaller diameter. This results in lower packaging and transportation costs, as well as a reduced carbon footprint.

     

  7. Cost Efficiency: The advanced design of SiroccoHD and Sirocco Extreme cables helps lower both installation and operational costs. The ease of installation and reduced need for specialist engineers contribute to significant cost savings.

     

By integrating these innovative features, Prysmian has created optical fibre cables that meet the demands of modern telecommunications and data networks, ensuring high performance, reliability, and efficiency.

 

SiroccoHD and SiroccoExtreme datasheets are avaliable at the link below:

Sirocco Datasheets