You may not know it, but fiber optics have a big impact on your every day life. Fiber optics are the engine behind today’s high-speed communication; whether you are talking on the phone, watching TV, or spending hours on the internet, fiber optics make it all possible.
Fiber Optics connect our world
But what is fiber optics? How do fiber optics work?
Let’s start with the fiber optics definition: Fiber optics (or optical fibers) are long, thin strands of very pure glass about the diameter of a human hair. Fiber optic strands are arranged in bundles within fiber optic cables, which are used to transmit light signals over long distances. These light signals carry vast amounts of information to cable, telephone, and internet providers, who then transmit the signals to your house, granting you cable, telephone, and internet access. The light signals carrying information travel very fast within the fiber optic cable, allowing you to have high-speed internet. For example, when you’re searching for something in Google and your results pop up within a matter of seconds, that is thanks to fiber optics.
Fiber Optic Strands
What is a fiber optic cable?
A fiber optic cable is comprised of fiber optic strands and is made up of the following parts:
- Core – Very small, thin glass center of the fiber optic cable where light travels.
- Cladding – Outer optical material surrounding the core that reflects the light back into the core, keeping the light within the cable.
- Buffer coating – Plastic coating around the cladding that protects the fiber from damage and moisture.
Fiber Optic Cables
What are the types of fiber optic cables?
There are many different types of fiber optic cables, which can be classified in several ways, however the most basic classification is according to the size of their core:
- Single mode fibers have small cores, which allow the light within the core to stay more focused as it travels. Therefore, less information is lost. For this reason, single mode fibers are used to transmit light over long distances.
- Multimode fibers have larger cores, which causes increased dispersion of light as it travels within the core. This results in more information being lost, which is the reason multimode fibers are used to transmit light over shorter distances.
How does light travel within a fiber optic cable?
The light in a fiber optic cable travels through the core by constantly bouncing from the cladding, a principle called total internal reflection. Because the cladding does not absorb any light from the core, the light wave can travel across distances. However, some of the light signal degrades within the optical fiber as it travels, mostly due to impurities in the glass. The extent that the signal degrades depends on the purity of the glass and the wavelength of the transmitted light
How is information transmitted inside a fiber optic cable from one location to another?
Fiber optic cables are connected to optical transceivers (or fiber optic transceivers) that can send and receive information through the cable. Inside each optical transceiver is a transmitter that can transmit data and a receiver that can receive data. Transceivers can receive information in the form of an electric signal, convert it to an optical signal, and then transmit that signal through the fiber optic cable, and vice versa. This is important because all of our electronic devices (i.e. cell phones, televisions, computers), as well as our servers, work with electrical signals. Therefore, transceivers enable information to travel to and from our electronic devices at the speed of light, thus creating reliable, high-speed connections.
What types of transmitters are in optical transceivers?
Three types of transmitters that are found in optical transceivers, and all three transmit light in different ways:
- LED: LED’s have limited bandwidth and poorly focused light, which causes more information to be lost per kilometer. Thus, LED transmitters are used in multimode fibers to transmit light over very short distances.
- VCSEL: VCSEL’s have better bandwidth than LED’s and have more focused light. VCSEL transmitters are also used in multimode fibers to transmit light over short distances.
- Laser: Laser’s have high bandwidth and very focused light, which allows for more information to be transmitted per kilometer. Thus, Laser transmitters are used in single mode fibers to transmit light over long distances.
What are some types of fiber optic equipment?
Fiber optic cable connectors
Optical transceivers connect to fiber optic cables using fiber optic cable connectors. There are many types of connectors, but the most common connectors used with transceivers are LC Connectors and SC Connectors. LC connectors are most universally used, while SC connectors are most often used to connect fiber optic cables with old transceivers and power meters. Less common connector types are FCs and STs.
Fiber Jumpers Fiber jumpers are very short fiber optic cables that usually span the length of a few meters. They are used to transfer fiber optic signals between very small distances.
Fiber optic power meters are used to measure the power of an optical signal at a specific wavelength. Some fiber optic power meters can measure different wavelengths at the same time, and show graphics.
Fiber Optic Power Meters
Fiber Optics are Awesome!
So remember, the next time you’re chatting away on your cell phone, enjoying your favorite TV show, or searching for information on the web, you can thank fiber optics for making high-speed communication possible!
Written by: Danielle Yannotti and Diego Del Gallego
745 Albany Shaker Road
Latham, NY 12110