How to distinguish whether the optical fiber module is single-mode or multi-mode?

As an important part of optical network transmission, optical fiber module is used for photoelectric conversion, so that signals can be transmitted in optical fiber. Do you know how to distinguish whether the optical fiber module is single-mode or multi-mode? Here are some methods to distinguish multimode fiber modules from single-mode fiber modules.

First, we can see the wavelength parameters of the optical fiber module. Generally, the wavelength of the optical fiber module is 850nm, so the optical fiber module is a multimode optical fiber module. The wavelength of single-mode optical fiber module is generally 1310nm, 1330nm, 1490nm, 1550nm, etc. In addition, CWDM color optical module and DWDM color optical module are single-mode optical fiber modules.

Second, we can see the transmission distance of optical fiber module. The transmission distance of multimode optical fiber module is generally less than 2km, which needs to be used with multimode optical fiber jumper. The transmission distance of the single-mode optical fiber module is generally more than 2km. The gigabit single-mode optical fiber module can be transmitted to 160km at most, and the gigabit single-mode optical fiber module can be transmitted to 100km at most.

Third, we can see the type of optical components of the optical fiber module. The optical transmitter of the multimode optical fiber module is VCSEL, while the optical transmitter of the single-mode optical fiber module is DFB, EML, FP, etc.

Fourth, we can judge whether single-mode or multimode is based on the pull ring color of the optical fiber module. The pull ring color of multimode optical fiber module (excluding 40G) with transmission rate below 40G is generally black, and the pull ring color of multimode optical fiber module (including 40G) with transmission rate above 40G is cream. The color of the pull ring of the single-mode optical fiber module with the wavelength of 1310nm is blue. In addition, there are other color pull rings. They are single-mode optical fiber modules.