Optical fiber is a medium that transmits information from one end to the other. It is a glass or plastic fiber that serves as a transmission medium through which information passes.

The terms "optical fiber" and "optical cable" are often confused. Most optical fibers must be covered by several layers of protective structures before use, and the covered cable is called an "optical cable." The protective structure on the outer layer of the optical fiber can prevent damage to the fiber from the surrounding environment, such as water, fire, electric shock, etc. Optical cables are divided into: optical fiber, buffer layer, and coating. Optical fiber is similar to coaxial cable, except that it has no mesh shielding layer. The center is the glass core through which light propagates. In multimode fiber, the core diameter is 15μm to 50μm, which is roughly the thickness of a human hair. The core diameter of single-mode fiber is 8μm to 10μm. Surrounding the core is a layer of glass cladding with a lower refractive index than the core, to keep the light inside the core. Outside that is a thin plastic jacket to protect the cladding. Optical fibers are usually bundled into strands with an outer shell for protection. The core is usually a double-layer concentric cylinder with a very small cross-sectional area made of quartz glass, which is brittle and easily broken, so an additional protective layer is required.

Characteristics of Optical Fiber

Since optical fiber is a transmission medium, it can transmit data such as telephone calls or computer data like ordinary copper cables. The difference is that optical fiber transmits optical signals rather than electrical signals. Therefore, optical fiber has many unique advantages.

Such as: wide bandwidth, low loss, shielding electromagnetic radiation, light weight, security, and privacy.

Operation of Optical Fiber Systems

You may know that any communication transmission process includes: encoding, transmission, and decoding. Of course, the transmission process of optical fiber systems is also roughly the same. After the electrical signal is input, the transmitter digitally encodes the signal into an optical signal. The light is transmitted through the optical fiber as a medium to the receiver at the other end, and the receiver decodes the signal and restores it to the original electrical signal output.

Application of Optical Fiber Cables

Optical cable applications can be divided into three categories: professional use, general outdoor, and general indoor. Professional applications include submarine cables, aerial cables on high-voltage towers, radiation-resistant cables for nuclear power plants, and corrosion-resistant cables for the chemical industry. The difference between general indoor and general outdoor classification depends on the characteristics of each type of optical cable during manufacturing and design, and their applicable scopes vary.

With the continuous advancement of technology, optical fiber communication technology has made great progress in modern applications such as telecommunications, FTTH (Fiber to the Home), 5G communications, data centers, and the Internet of Things, becoming an indispensable infrastructure for the information society.