Vertical-cavity surface-emitting lasers with incorporated photonic crystals for transverse mode control

摘要

Existing problems in the development of vertical-cavity surface-emitting lasers with photonic crystals (PC-VCSELs) for transverse mode control are reviewed. The theoretical background of VCSELs with PCs incorporated within their top distributed Bragg reflector (DBR) (type I PC-VCSELs) and VCSELs with PCs incorporated within their cavity (type II PC-VCSELs) is introduced. Their fabrication using focused ion-beam (FIB) etching is discussed. It is shown that type I single-mode PC-VCSELs suffer from low optical power and poor small-signal modulation performance due to the reduction of the reflectivity of the top DBR introduced by the PC. The problem is expected to be reduced in type II PC-VCSELs that are being investigated now. One approach to the fabrication of type II PC-VCSELs is described.