The optical module is an important component of the optical fiber communication system, which is used to realize the transmission and reception of optical signals. The speed of the optical module used in the data center ranges from 1G before 2010 to the commonly used 10G and 40G now.

Since most of the equipment distance in medium and large data centers is within 500 meters, the interconnection between equipment generally uses multi-mode fiber (OM3, OM4), the light source of the multi-mode optical module uses VCSEL laser as the emitting light source, and PIN as the optical receiver.

At present, the optical interconnection between the server and the access switch in the access layer mainly adopts 10G SFP+ optical modules, and the switch interconnection between the access layer and the aggregation layer/core layer mainly adopts 40G QSFP+ optical modules.

Next, ETU-LINK will introduce several common 10G SFP+ optical modules and 40G QSFP+ optical modules in data centers.

1、10G SFP+ dual fiber optical module

2、40G QSFP+ optical module

The interconnection between data center network elements and equipment mostly uses multi-mode fiber. Although the price of multi-mode fiber is more expensive than single-mode fiber, the transmission bandwidth is not as high as single-mode fiber, and the attenuation is greater than single-mode fiber. However, because the price of multi-mode optical modules is relatively cheaper than single-mode optical modules, indoor multi-mode optical fiber communication systems have a great comprehensive cost advantage over single-mode optical fiber systems.