We often find Huawei transmission optical modules in the description of the single board is I-x or Ie-x (x represents a different rate), on behalf of the bureau of communication, it should be a multimode optical port, but the wavelength is often not 850nm, but 1310nm, so what are the main differences between the 1310nm single-mode optical module and 1310nm multimode optical module.

Processing

According to the principle of multi-mode, single-mode division can be found 1310nm multi-mode optical module and single-mode optical module main differences are as follows:

1, single-mode modules generally use LD or spectral lines narrower LED as a light source, coupling components size and single-mode fiber with good, using single-mode fiber transmission can transmit longer distances.

2, multi-mode modules generally use lower-priced LED as a light source, coupling parts size and multi-mode fiber with good.

3, different optical modules to send the signal wavelength is 1310nm but the optical power power is different.

4, the extinction ratio of the multi-mode optical module is larger than the single-mode optical module, the refractive index is also different.

Root cause

Multimode optical fiber is divided into multimode mutant fiber and multimode gradient fiber. The former core diameter is larger, more transmission modes, thus narrower bandwidth, smaller transmission capacity; the latter core in the refractive index with the increase in radius and reduce the modal dispersion can be relatively small, thus wider bandwidth, larger transmission capacity, the latter are generally applied.

Due to the different modes of light in the multi-mode fiber with different transmission speeds, so the multi-mode fiber transmission distance is very short. And single-mode fiber can be used in no relay optical communication.

In fiber optic communication theory, optical fiber has single mode, multi-mode points, the difference is:

1, single-mode fiber core diameter is small (10m m or so), allowing only one mode transmission, small dispersion, working at long wavelengths (1310nm and 1550nm), and the coupling of optical devices is relatively difficult.

2, multi-mode fiber core diameter (62.5m m or 50m m), allowing hundreds of modes of transmission, dispersion, working at 850nm or 1310nm. coupling with optical devices is relatively easy.

As for the optical module, strictly speaking, there is no single-mode, multi-mode points. The so-called single-mode, multi-mode module, refers to the optical module using optical devices and what kind of fiber with the best transmission characteristics.