25G SFP28 SR optical modules typically use multi-mode fiber and can transmit over shorter distances, up to 100 meters. They are commonly used for communications within a data center or between devices that are in close proximity to each other. Since these modules are designed for short-range transmissions, they consume less power than LR modules and are thus more energy-efficient.
On the other hand, SFP28 LR optical transceiver modules use single-mode fiber and can transmit over much longer distances, up to 10 kilometers. They are ideal for long-haul telecommunications applications where data needs to be transmitted over a greater distance. However, due to the longer transmission distances, LR transceiver modules require more power and have a higher cost compared to SR transceiver modules.
Another important difference between the two modules is the type of laser used. SR modules use Vertical Cavity Surface Emitting Lasers, which offer lower power consumption and lower cost. In contrast, LR modules use conventional FPLs or Distributed Feedback lasers, which provide higher output power and longer transmission distances.
In summary, the primary differences between 25G SFP28 SR and SFP28 LR optical transceiver module are the maximum transmission distance, the type of fiber used, the power consumption, and the type of laser used. Network administrators should consider these differences when selecting the appropriate module for their specific application requirements.