Optical fiber is a medium that transmits information from one end to the other. It is a glass or plastic fiber that acts as a transmission medium for messages to pass through.
Usually, the terms "optical fiber" and "optical cable" are confused. Most optical fibers must be covered by several layers of protective structure before use. The covered cable is called "optical cable". The outer structure of the optical fiber can be protected. Prevent the damage of the surrounding environment to the fiber, such as water, fire, electric shock, etc. The cable is divided into: fiber, buffer layer and coating. The fiber and coaxial cable are similar, but there is no mesh shielding layer. The center is the light-transmitting glass core. In a multimode fiber, the diameter of the core is 15 μm to 50 μm, which is roughly equivalent to the thickness of human hair. The single mode fiber core has a diameter of 8 μm to 10 μm. The outside of the core is surrounded by a glass envelope having a lower index of refraction than the core to maintain the fiber within the core. Next to it is a thin plastic jacket to protect the envelope. The fiber is usually bundled and protected by an outer casing. The core is usually a double-layer concentric cylinder made of quartz glass with a small cross-sectional area, which is brittle and easily broken, so that a protective layer is required.
Since fiber is a transmission medium, it can transmit data such as telephone calls or computer data like a normal copper cable. The difference is that the optical fiber transmits optical signals instead of electrical signals. Therefore, optical fibers have many unique advantages.
Such as: wide bandwidth. Low loss. Shield electromagnetic radiation. Light weight. Safety. Concealment.
Fiber optic system operation
You may know that any communication transmission process includes: encoding → transmission → decoding. Of course, the transmission process of the optical fiber system is also roughly the same. After the electronic signal is input, the signal is digitally encoded by the transmitter to become an optical signal, and the light is transmitted through the optical fiber. The medium is transmitted to the receiver at the other end, and the receiver decodes the signal and restores it to the original electronic signal output.
Application of fiber optic cable
The application of optical cable can be divided into three types: professional use, general outdoor, general indoor. In professional use, including submarine optical cable, empty optical cable on high voltage electric tower, anti-radiation optical cable of nuclear power plant, anti-corrosion of chemical industry Optical cable, etc.. The difference in classification between general and general indoors, depending on the characteristics of each type of optical cable, depends on the scope of application.