In-phase evanescent coupling of two-dimensional arrays of defect cavities in photonic crystal vertical cavity surface emitting lasers

In-phase evanescent coupling in $2×1$ and $2×2$ arrays of defect cavities in photonic crystal (PhC) vertical cavity surface emitting lasers (VCSELs) is reported. Two-dimensional PhC patterns of air holes containing multiple defects are etched into the top distributed Bragg reflector of VCSELs. The resulting modification of the effective index and optical loss results in evanescent coupling between the multiple defect cavities of the PhC VCSEL. Far field measurements and simulations show good agreement and demonstrate the in-phase results.