Effects of packaging parasitics on high speed operation of VCSELs

In the present work the current-pulse as well as the voltage-pulse mode of operation of VCSELs are investigated. Using an accurate non-linear circuit VCSEL model, which includes internal and packaging parasitics a consistent comparison between the two configurations at 2 Gbps operation was performed. It demonstrated the need for an accurate prediction of parasitic elements since they are critical for the normal operation at high speeds. It is also shown that current driving mode is inadequate in comparison with voltage driving for VCSELs operating at 2 Gbps or higher, especially when the common laser packages are proven to be unable to support high data speeds.