As an important part of fiber optic network transmission, optical fiber module plays an important part. It can fullfill the photoelectric conversion, so that signals can be transmitted in optical fibers. 

The Optical fiber module in market now mostly have two types. single-mode and multi-mode.

This essay will introduce few fast ways to distinguish between multi-mode fiber modules and single-mode fiber modules.

1st, by wavelength. We can look at the wavelength parameters of the optical fiber module. Generally, if the wavelength of the optical fiber module is 850nm, then the optical fiber module is a multimode optical fiber module. Because the wavelength of the single-mode optical fiber module is generally 1310nm, 1330nm, 1490nm, 1550nm, etc. In addition, the CWDM color light module and DWDM color light module are both single-mode fiber modules.

2nd, we can look at the transmission distance of fiber optic modules. The transmission distance of multimode fiber optic modules is generally less than 2km, which needs to be used with multimode fiber jumpers. While the transmission distance of a single-mode optical fiber module is generally above 2km, a Gigabit single-mode optical fiber module can transmit as far as 160km, and a 10-Gigabit single-mode optical fiber module can transmit as far as 100km.

3rd, we can look at the types of optical components of the fiber optic module. The light emitting device of the multimode fiber optic module is VCSEL, and the light emitting device of the single mode fiber optic module is DFB, EML, FP, etc.

last but not the least, we can judge the single-mode or multi-mode from the color of the pull ring of the fiber optic module. The color of the pull ring of the multimode fiber optic module with a transmission rate of less than 40G (excluding 40G) is generally black, 40G and above (including 40G) The color of the pull ring of the multimode fiber optic module is beige. The pull ring of the single-mode fiber module with a wavelength of 1310nm is blue. In addition, there are other colors of pull ring. which mostly are for single-mode fiber modules.such as violate.green. etc.

Knowing the fiber type (single-mode/multi-mode) of the fiber optic module helps us to choose the corresponding fiber jumper correctly.