Travelling at the Speed of Light

Fiber optics is not a new concept, but it has taken a couple hundred years to perfect it. As early as the 1790s, the Chappe brothers invented the first “optical telegraph”. The French duo were able to relay messages through a series of lights mounted on towers. Then in the 1840s and 50s British physicists discovered that you could direct light along jets of water and even bend it along curved streams of water. Alexander Graham Bell, improving on his telephone, patented the “photophone” in 1880, which was an optical telephone system. Viennese and American doctors worked on bent or curved glass rods to illuminate body and mouth cavities.

Then in 1930, a Jewish physician, Heinrich Lamm, became the first to transmit an image using a bundle of optical fibers. This concept was brought along with the invention of lasers and then finally single mode fiber was made in 1970 by Corning Glass Works. Advancing fiber further, in 1973 Bell Laboratories developed the standard process for which fiber-optic cables are manufactured. 

185 years from the Chappe brothers optical telegraph, the UK’s Dorset police install the first fiber optic link, followed in California US two years later with the first fiber optics telephone traffic. More US telephone companies followed suit and the mid-1980s saw the emergence of the very first nationwide, 100% digital fiber optic network, Sprint. Going global was made possible in 1986 with low-cost long distance fiber systems and in 1988 the first transatlantic telephone cable went into operation. 

In 1997, Fiber Optic Link Around the Globe (FLAG) became the world’s longest single-cable network creating the infrastructure for future generations of broadband communications. One of the greatest advantages of fiber is it is future ready as it has no foreseeable replacement, nor need for one. Fiber currently meets all internet application needs and will continue to do so indefinitely.

What Exactly is Fiber?

Fiber is made of thin strands of pure glass which makes it resistant to corrosion and gives it longevity that will surpass that of copper or coaxial cable. The glass also makes fiber immune to electromagnetic and radio interference so you would not experience any shorting or grounding issues. And the capacity of fiber is unprecedented – a pencil thin bundle of fiber, called an optical cable, is capable of managing the entire world’s telephone traffic. 

A single strand of optical fiber is made of three parts – the core, cladding, and buffer coating. The core is the center through which the light travels and is made of very fine strands of glass. The cladding is what surrounds the core and reflects light inward allowing light to pass through bends and avoid signal loss. And the buffer coating is a plastic coating protecting the entire optical fiber from moisture and damage. Bundling hundreds or thousands of these optical fibers together builds an optical cable, which has an outer covering, called a jacket, to protect them. 

There are two types of optical fibers – single-mode and multimode. Single mode fiber has a smaller core and is generally used for long distance transmissions using laser diode fiber optic transmission equipment. Multimode fiber has a larger core and is generally used for short distance transmissions using infrared light from LEDs (light emitting diodes). For close distances of a few miles, multimode fiber is the best option. When distances are greater, single mode should be used.

How Does Fiber Work?

In simple terms, pulses of light containing digital information travel from one place to another across the fiber. The equipment on one side of the fiber network converts signals into pulses of light that run along the fiber strands at an incredible speed. The equipment on the opposite end receives and decodes the pulses of light. For example, if the fiber is travelling to your home, the signals are transformed into signals you can hear, read, or watch on your computer, TV or other electronic device like your phone or tablet.

Each particle of light, or photon, travels through the fiber optic cable core, reflecting back inward every time it hits the fiber’s edge. This is called total internal reflection. As long as the light hits the edge at anything other than the critical angle, it will remain trapped inside and continue along its path. The critical angle for most glass is 42o.

The cladding that surrounds the core helps keep the light signals inside the core. Cladding is also made of glass, but a different type of glass from the core. The cladding has a lower refractive index than the core which helps increase the critical angle. Cladding also helps protect the core, lessen the reflections which lowers energy loss and transmission time.

All of this means that with a fiber network in your home feeding your internet, phone, and TV, you will experience high-speed internet access, crystal clear phone service, and sharp, reliable digital TV. Even over enormous distances, fiber optic signals never lose their strength.

Clean Fiber Optic Communication Systems are Essential

Fiber optic switches, networking, and transmission equipment are critical to the reliability of the communications network. These systems route voice, video, and data we rely on every day, and contain sensitive circuit boards which generate considerable heat within confined spaces. Wattage dissipation is crucial in order to keep these systems cool. Typically, fans are used to introduce cooling air which maintain the specific temperature range to allow the system to operate at peak efficiency. 

It is important to keep the cooling air clean and evenly distributed within the system, so considerable design and evaluation are devoted to electronics cooling and thermal management through thermal simulations and testing. Dust contaminants range in size, weight, and compounds. If the dust enters the system and builds up on critical electronic components, wattage increases, circuit boards could fail, and service is lost. This is where Universal Air Filter can help. They offer a wide array of quality air filter media and designs that meet stringent telecommunications standards for flame safety and reliability. The air filters are designed to keep the system clean, maximize cooling air flow, and compliant with industry requirements. Taking into consideration the sophistication of fiber optics, it is imperative to keep equipment clean and network uptime protected with the right filter for the system.