The rapid innovation and progress we see today are mostly due to digital technology that depends on faster and efficient data transmission. Fiber optic is regarded as one of the fundamental elements in the seamless and fast transmission of data and information from one place to another.
The communication we see today has come a long way since Graham Bell first built the telephone, and now we see wireless communication. Fiber optics have more or less replaced the traditional copper wires and are now considered the backbone of cellular and digital networks.
The Importance of Fiber Optic Cable
The fast data transfer capabilities, large carrying capacity, affordable maintenance, and ability to cover long distances make fiber optics the number one choice for digital communication in various walks of life from businesses, universities, cable television, industrial plants, and electric utility companies. Fiber optic is used
- To boost data speed in computer networking
- In medical surgery and dentistry
- Improve the bandwidth of internet connection
- Enhancing the cable television experience
A typical fiber optic cable uses light pulses to transmit data and information. The light pulses move through the fiber optic cable made of glass or plastic through a process called ‘total internal reflection’, which states that once the angle of incidence exceeds a critical value, then the light will not escape from the glass and instead bounce back.
A single transmitter is placed at one end that accepts the coded electronic pulse information and translates the information in coded light pulses. The light pulses are generated by a light-emitting diode (LED), and using a lens, the light pulses are directed into the fiber optic cable through the core.
Types of Fiber Optic Cable
Transparent glass and plastic fibers are mostly used to ensure light pulses movement over short or long distances with minimum loss. The three types of fiber optic cable include ‘Plastic optical fiber, Single-mode, Multi-mode’ fiber cables.
The single-mode fiber optic cable is mostly used to transmit data over long distances, while the multi-mode is ideal for a short distance. Optical fibers mostly depend on the type of materials, refractive index, and mode of propagation of light.
The refractive index classification gives two types of fibers that are ‘Step index’ and ‘Graded Index’. In step-index, the core surrounding the cladding has a single index of refraction, while in graded-index, the optical fiber’s refractive index decreases as the radial distance increases.
The glass fiber optic cable comprises very minute and fine glass fibers. The plastic fiber optic cable consists of polymethylmethacrylate to transmit light.
The propagation of light and selection of material leads to four types of optic fiber cables, which are
- Single-mode – step-index
- Single-mode – graded-index
- Multi-mode – step-index
- Multi-mode – graded-index
Fiber Optic Providers in the USA always look to develop fiber optic cables with the advancement of technology. One of the progress is the fabrication of optical fibers through different methods and processes that include fiber coating, fiber drawing, fabrication, and spooling.
Mostly silica material is used because silica has the best elasticity level when it reaches a breaking point, ideal for the fabrication process.
The Difference between Single-mode and Multi-Mode
In fiber optic, ‘attenuation’ is another crucial aspect that means the loss of signal intensity. Glass fiber is used for long-distance because it has lower attenuation and plastic for the short distance with higher attenuation. The three factors that cause attenuation in optical fiber are absorption, waveguide effect, and scattering.
The difference between single and multi-mode optical fiber depends on core diameter, bandwidth, distance, wavelength, color sheath, and cost.
The single-mode core diameter is 9 µm and smaller than the multi-mode, which is 50 µm and allows increased light propagation. However, the cladding diameter of both single and multi-mode is 125 µm.
The bandwidth of a single-mode is unlimited as only one light is passed through the optical fiber cable. The multi-mode optical fiber cable’s bandwidth is limited due to the light mode, but the maximum bandwidth is calculated at 28000 megahertz per kilometer (MHz*km).
Single-mode fiber mostly uses laser diodes or lasers to inject the light pulses, and the wavelength is between 1310 nm (nanometers) to 1550 nm. In multi-mode cable, LEDs have used that range from 850 nm to 1300nm.
The single-mode fiber has a yellow outer color sheath, while the multi-mode fiber has an aqua or orange color sheath.
The application of single-mode fibers requires transceivers with lasers that operate over long distances and with higher wavelengths and narrow spectral width. The cost of multi-mode transceivers is twice time low as that of single-mode transceivers.
Due to the core sight and a different number of light modes, the single and multi-mode cannot be connected and, if done, will lead to a considerable optical loss. The single-mode fiber is an integral element of the telecommunication industry all across the world.
The recent advancement in optical fiber is the introduction of ‘Hollow-Core Optical Fibers (HCF), where the light pulses are passed through a vacuum core or air. HCFs have been stated as the future of sending high-speed data due to their lower dispersion and low latency as compared to solid fibers.