High-Speed Modulation of Index-Guided Implant-Confined Vertical-Cavity Surface-Emitting Lasers

An etched photonic crystal (PhC) or holey wedge structure induces index confinement into 850-nm implant-confined vertical-cavity surface-emitting lasers (VCSELs) to engineer the spatial overlap between the optical mode and laser gain for improved high-speed operation and reduced relative intensity noise. Large-signal operation of 12.5 Gb/s is achieved with a single transverse-mode PhC VCSEL and 15 Gb/s with a single transverse-mode holey VCSEL. An excessive current diffusion effect is found when the difference between the electrical and optical diameter is large (> 4 mu m), which limits the large-signal modulation of single-mode VCSELs. The design rules for optimal single transverse-mode high-speed PhC and holey VCSELs are extracted from a parametric study of their large-signal modulation characteristics.