Fiber optic is the abbreviation for optical fiber (OF). However, in optical communication systems, Optical Fiber is often simplified as Fiber, such as Fiber Amplifier or Fiber Backbone. Some people overlook that although Fiber has the meaning of fiber, it refers to optical fibers in optical systems. Therefore, it is clearly not advisable to directly translate 'fiber' as' fiber 'in the description of some optical products.

Fiber optic refers to a medium in which a core made of transparent material and a cladding made of a material with a slightly lower refractive index than the core are used to cover it, and the optical signal entering the core is reflected at the cladding interface, allowing the optical signal to propagate forward in the core.

There are many types of optical fibers, and the required functions and performance vary depending on their applications. But for fiber optic cables used in cable television and communication, the principles of design and manufacturing are basically the same, such as: ① low loss; ② Has a certain bandwidth and low dispersion; ③ Easy wiring; ④ Easy to unify; ⑤ High reliability; ⑥ Manufacturing is relatively simple; ⑦ Affordable prices, etc.

The classification of optical fibers is mainly based on the working wavelength, refractive index distribution, transmission mode, raw materials, and manufacturing methods. Here are some examples of various classifications.

(1) Working wavelengths: UV fiber, visible fiber, near-infrared fiber, infrared fiber (0.85pm, 1.3pm, 1.55pm).

(2) Refractive index distribution: step (SI) type, near step type, gradient (GI) type, others (such as triangular, W-shaped, concave, etc.).

(3) Transmission modes: single-mode fiber (including polarization maintaining fiber and non polarization maintaining fiber), multi-mode fiber.

(4) Raw materials: quartz glass, multi-component glass, plastic, composite materials (such as plastic cladding, liquid fiber core, etc.), infrared materials, etc. According to the coating material, it can also be divided into inorganic materials (carbon, etc.), metal materials (copper, nickel, etc.), and plastics.

(5) Manufacturing methods: Pre molding includes vapor axial deposition (VAD), chemical vapor deposition (CVD), etc. Drawing methods include rod intube and double crucible methods.