The Topstar’s100Gb/s transceiver module for optical communication applications compliant to 100GBASE-SR4 of the IEEE P802.3bm standard. The module converts 4 input channels of 25Gb/s electrical data to 4 channels of VCSEL optical signals over 4 multimode fibers for 100Gb/s optical transmission. Reversely, on the receiver side, the module receives 4 channels of VCSEL optical signals over 4 multimode fibers and then converts them to 4 output channels of electrical data.