High Modulation Bandwidth Implant-Confined Photonic Crystal Vertical-Cavity Surface-Emitting Lasers

High-speed implant-confined photonic crystal vertical-cavity surface-emitting laser (VCSEL) diodes are fabricated and characterized. The maximum achievable 3-dB bandwidth is a function of both the index confinement provided by the etched pattern (which serves to reduce the diffraction loss and provide for stabilized fundamental mode operation) and the increased parasitic resistance caused by the removal of doped material. In optimized designs, the reduction in net loss provided by the etched pattern can more than offset the increased parasitics, resulting in a higher 3-dB bandwidth than possible in an unetched conventional implant VCSELs for both single- and multi transverse mode operation. A maximum 3-dB small-signal modulation bandwidth of 15 and 18 GHz is reported for an optimized single transverse-mode and multimode VCSEL, respectively.