How is Data Transmitted By Light Via Fiber Optic Cables

In the fast-paced world of technology, the transmission of data has evolved from traditional copper wires to the revolutionary use of light. 

The backbone of this transformation lies in fiber optic cables, which have become the go-to choice for high-speed and reliable data transfer. 

In this blog, we will unravel the mysteries behind how data is transmitted by light, the mechanics of fiber cables, and the ingenious measures in place to ensure the light's journey remains uninterrupted.

How is Data Transmitted by Light?

Let's strip down the complexity of fiber optic communication to its essence—ones and zeros, much like Morse code. 

The communication dance begins with short pulses of light, akin to a flashlight signaling in the dark. These light pulses, generated by laser diodes, represent binary data—0s and 1s—with their rapid switching allowing data to travel at breathtaking speeds.

Laser diodes are commonly used as light sources in fiber optic communication, emitting coherent beams of light with precision-tailored wavelengths. These wavelengths determine the color of the light, and within a single fiber optic cable, various wavelengths can dance together, facilitating the transmission of multiple data streams. 

Photo credit to Photonics.com

The core of the fiber optic cable welcomes these light pulses, and through intensity or phase modulation, data is embedded in the light, achieving data transmission at the speed of light.

These modulation techniques, combined with the speed of light, enable fiber optic cables to transmit vast amounts of data in fractions of a second.

As the light pulses journey through the fiber, they encounter couplers and splitters, managing the distribution of data to different destinations. 

At the receiving end, photodetectors transform optical signals back into electrical ones, allowing electronic devices to interpret and process the data seamlessly.

How Do Fiber Cables Carry Data?

Fiber optic cables are the conduits through which light travels to carry data across vast distances. These cables consist of a core made of glass or plastic fibers, surrounded by a cladding layer that reflects the light inward, preventing signal loss.  Think of it as a protective buffer, shielding the core and cladding from potential data-disrupting hazards.

The core's cleverly designed refractive index ensures total internal reflection, allowing the light to bounce within the core, faithfully transmitting the data. It's a well-choreographed dance of light, maintaining the integrity of the signal throughout the cable's journey.

How Does Light Not Die Out Over Long Distances?

If you were to shine a light in a dark forest, you’d notice that you only have a small amount of light.  How then if fiber optic cabling able to achieve passing light over such long distances, and still be able to transmit and retain the data

Photo credit to researchgate.net

This minimal signal loss over long distances is one of the remarkable features of fiber optics. 

This occurs thanks to a phenomenon known as total internal reflection.  The structure of fiber optic cables, the core and cladding, allows the light to bounce internally without losing data until it reaches its destination.  

How do Repeaters and Amplifiers Help boost light signals?

To ensure the light remains vibrant, repeaters or amplifiers strategically placed along the cable act as boosters, compensating for any signal loss through attenuation that naturally occurs over long distances.  These methods involve turning the light into binary signals, and then back into light to boost its strength.

The use of repeaters at points where the signal may weaken ensures that the signal remains strong and clear, even across transcontinental data highways.

Amplifiers, equipped with optical fibers and special chemicals, amplify the light, ensuring it retains its strength as it travels across transcontinental data highways. It's like a relay race for light, where each baton pass ensures the data remains strong and clear.

How Does Light Bounce and Not Lose Data?

The phenomenon of total internal reflection is the key to ensuring that light bounces within the fiber core without losing data. 

When light encounters the boundary between the core and cladding at a certain angle, it reflects back into the core rather than escaping through the cladding. This process allows the light signals to traverse the entire length of the fiber without significant signal degradation.

Photo credit to mamothmemory.net

If you were to shine a single beam of light, in the same way a singlemode fiber strand would, you would see the light go straight through the core.  If you change the angle of the beam of light, the light would begin bouncing, or reflecting, within the core to reach its destination.

Singlemode fibers are designed to be smaller and have less reflecting within the cable, allowing it to go longer distances.  When you have more bouncing around like the image above, your light would be traveling within a multimode fiber.  Being able to transfer many rays of light through fiber allows us to transfer more and more data from one point to the other.

What Measures Need to Be in Place to Keep the Light Working?

Maintaining the integrity of light-based data transmission requires a symphony of measures. 

High-quality materials for fiber optics, precise manufacturing techniques, and rigorous testing identify and replace faulty components. 

Environmental factors such as temperature and humidity are carefully controlled to ensure optimal performance, ensuring the light's journey remains harmonious.

How Much Can Fiber Bend Without Losing Data?

Fiber optic cables are surprisingly flexible, and their ability to bend without losing data is a crucial advantage. 

Each cable that we sell has a specific bend radius within the spec sheets to indicate how much they can bend without losing the signal or breaking.

While fiber strands can have a high bend radius, keep in mind that they are still fundamentally made of glass and glass can crack.  The cables can bend more than you think, but avoid kinking or over bending in any installations to reduce signal loses of data.

The level of flexibility, known as the bend radius, depends on the type of fiber and its construction. 

Single-mode fibers, commonly used for long-distance communication, have a smaller bend radius compared to multi-mode fibers. 

Careful installation and handling are essential to prevent excessive bending that could lead to signal loss.

Fiber communication vs electromagnetic communication

If your home has a fiber connection for the internet, you may notice that the cabling is often in the same place outside your home as electric wires.

Because fiber does not cause electromagnetic interference to things around it, it's possible to put these cables side by side. This unique quality allows for efficient data transfer without occupying excessive space.  

Fiber cabling makes it possible to transfer much more data without taking up much more space.  These cables are often very heavy by comparison however, so they will need assistance with aerial OSP installations.

That being said, fire hazards and other perils are something to consider when pairing these cables in close proximity.

Conclusion:

Hopefully this blog shed some light beams on the remarkable ways in which this technology illuminates our world.

The dance of light through fiber optic cables is a testament to human ingenuity, connecting us across vast distances at speeds once thought impossible. Here's to the future where light continues to pave the way for a more connected and enlightened world.