What are the main welding machine used in optical fiber type?
Points: 1, according to the transmission frequency window of conventional single mode fiber and dispersion-shifted single-mode fiber.
Conventional type: fiber manufacturers will be optical fiber transmission frequency on the single wavelength of light, such as 1300 microns.
Dispersion-shifted type: fiber manufacturers will be optical fiber transmission frequency on the two wavelengths of light, such as: 1300 microns and 1550 microns.
2, according to the refractive index distribution points: mutation type and gradual type optical fiber.
Mutant: fiber optic center core to the refractive index of glass cladding is mutation.
Its low cost, high modulus between the dispersion.
Suitable for short-distance communication at low speed, such as industrial control.
But dispersion between single-mode fiber due to mould is very small, so the step-index single-mode fiber are adopted.
Graded-index optical fiber, optical fiber core center to the refractive index of glass cladding is gradually become smaller, can make the anti-embrittlement light transmission, the form of the sine dispersion between this can reduce the mold, improve optical fiber bandwidth and increase transmission distance, but the cost is higher, the multimode optical fiber for the gradient type optical fiber.
3, according to the light in the optical fiber transmission mode can be divided into: single touch fiber and a multimode fiber.
Multimode fiber: teaching center glass core thick (
50 or 62.
, the light can pass various patterns.
But its mode dispersion is bigger, this limits the transmission of digital signal frequency, and with the increase of the distance will be more serious.
For example: 600 MB/KM optical fiber in 2 KM, only 300 MB bandwidth.
Therefore, the multimode optical fiber transmission distance is near, usually only a few kilometers.
Single-mode fiber: teach fine glass core centre (
Core diameter is commonly 9 or 10 microns)
, only the light of a pattern.
Therefore, dispersion between the mould is very small, for remote communications, but its chromatic dispersion plays a main role, so single-mode fiber have higher request for the spectral width and stability of light source, the spectral width is narrow, the stability is better.