Com es fabriquen els conductors de fibra òptica?
La producció de fibra òptica es divideix principalment en tres processos, a saber, dibuix de fibra òptica, proves i preparació de preformes.
Preparació de preformes:
There are many process technologies for preform production, mainly including MCVD, OVD, VAD and PCVD, among which the most commonly used is the MCVD process, which is also the focus of this article. The full name of MCVD in English is modified chemical vapor deposition. This optical fiber preform production process was developed by Bell Labs in 1974. The gaseous mixture composed of SiCl4 (silicon chloride), GeCl4 (germanium chloride) and other chemical substances is introduced into the quartz glass tube (cladding), and the quartz tube is rotated and heated, and the silicon and germanium are oxidized to form SiO2 ( Silica) and GeO2 (germanium dioxide) make it stay in the quartz tube to form the main part of the optical fiber.
In addition, parameters such as the refractive index, expansion coefficient, and melting point of the optical fiber can also be controlled by the component concentration of the gaseous mixture. After the preform is in a cooling state, its quality needs to be tested.
Dibuix de fibra:
Put the preform into the fiber drawing tower for drawing. The preform after drawing will become 125μm thick and thin optical fiber, and is coated with two layers of resin to protect the strength of the optical fiber. The structure of the fiber drawing tower includes a graphite furnace, which can produce a high temperature of 1700-2000 degrees, fully soften the preform, and wind it through the drawing wheel to make a more slender optical fiber.
The drawing tower can feed back the furnace temperature and winding speed, and accurately control the diameter of the fiber through a laser micrometer. In order to improve the strength of the optical fiber, the drawing process needs to coat the optical fiber with a thin layer of resin in time and dry it to avoid mutual adhesion.
Prova:
After drawing, it is essential to inspect the finished fiber. Test parameters include tensile strength, refractive index, fiber structure, attenuation, information carrying capacity (bandwidth), dispersion, operating temperature and humidity range, etc.