High-Speed Data over POF
High-speed data links over Graded-Index POF have been intense subjects of research, which delve into unique signalling schemes, transmitter and receiver hardware, and specialized fiber to achieve 1 Gigabit (Gbps) and higher. The technology behind these achievements is still in the development stages, but each experiment is a promising step towards fast and cost-effective POF networks for consumers.
Several standards are in place now that specify step-index POF as the physical media, such as 1000BASE-H (physical layer) and IEEE 802.3bv (data link layer), that achieve Gigabit link speeds through the use of advanced signal processing, error correction, and modal power distribution. This builds on 100BASE-FX, which is the original physical layer standard for Fast Ethernet over POF.
POF brings several key advantages over other mediums to every application that it is used in: Safe troubleshooting with visible light spectrum transmitters, and resiliency to handling and bending during installation.
The following frequently asked questions tackle the ins and outs of high-speed fiber optic networks.
How is optical fiber used in communication systems?
In large-scale communication systems, including the Internet, optical fiber is often used in the backbones that provide long-distance, high-bandwidth links between parts of the network. Fiber optics are also ideal for segments of telecommunication systems that have to pass data through locations with high amounts of electromagnetic interference.
After passing through these high-bandwidth backbones, the data is converted back to electrical signals for transmission to the ultimate endpoint.
What is a fiber optic network?
A fiber optic network is a complete communication system based on fiber optic equipment. It consists of transmitters and receivers that convert between electrical and light signals, network switches, relays, amplifiers, and the fiber optic cable itself. Networks like these can be specialized for industrial or scientific purposes, or designed for more general purposes like delivering broadband internet to homes or businesses.
What is fiber optic broadband?
Fiber optic broadband is broadband internet service that is delivered entirely over fiber optic cables, from the service provider to the customer. While fiber optic communication has been an important part of the internet for decades, a fiber optic connection directly to a home or business is a relatively new alternative to broadband (cable-based) or DSL (phone line-based) connectivity methods, and is growing in availability and popularity. Besides being able to offer the fastest internet speeds available, it is also regarded as future-proof because of the very high bandwidth that optical fiber can support.
How much data can a fiber optic cable carry?
In use cases like fiber optic broadband, a singlemode GOF cable supports a bandwidth of 1 gigabit per second. However, specialized applications of fiber optic technology have well surpassed this. As of 2012, NEC and Corning hold the record for data transmission bandwidth of 1.05 petabits per second, 1,000,000 times the capability of broadband fiber. This was achieved through the use of multicore fibers and a unique signal processing scheme on the transmitting and receiving ends of the network.
How is data transmitted over fiber optics?
At the transmitting end of a fiber optic communication system, the active component, typically a laser or LED, is coupled to the fiber optic cable through a connector. The light source is precisely directed into the core of the fiber to ensure that all of the light energy is transmitted through the cable.
To send data, the light is pulsed at rates too high for the human eye to detect. Depending on the application, different modulation techniques are used to convert electrical data into light that involve changing the light’s phase, polarization, and amplitude. The field of communication theory delves into the details of these transmission schemes.
On the receiving side, the fiber optic cable is coupled to a photodiode, which converts the light signal back to an electrical signal. The type of diode used depends on the wavelength of light that the transmitter uses, and the desired data transmission speed of the network.
How are fiber optic communications more secure?
Compared to conventional copper data cables, it is considerably more difficult to wiretap optical fiber without detection. This is because doing so requires either completely breaking the connection at the tap temporarily to insert a device, or exposing the light-carrying core or bending the fiber to divert the signal, which may introduce a significant amount of signal loss in the system. With this in mind, nearly-undetectable fiber tapping can still be performed by professionals with the right tools and techniques.
References
(2017) Fiber-Optic Internet In the United States at a Glance [Online]. Available: https://broadbandnow.com/Fiber
M. Peach. (22 January 2013) NEC and Corning achieve petabit optical transmission [Online]. Available: http://optics.org/news/4/1/29
(2014) The FOA Reference For Fiber Optics – How To Tap Fiber Optic Cables [Online]. Available: http://www.thefoa.org/tech/ref/appln/tap-fiber.html
M. Kagami, A. Kawasaki, S. Ito, T. Yamashita, M. Soga, M. Ogawa, “Standardization and Simulation Status of Automotive Optical Ethernet”, presented at the 27th International Conference on Plastic Optical Fibers, 2018, Seattle, Washington, U.S.A. 2018.