Theoretical investigation of transverse optical modes in photonic-crystal waveguides imbedded into proton-implanted and oxide-confined vertical-cavity surface-emitting lasers

We explain theoretically the influence of a two-dimensional photonic crystal (PC) defect waveguide imbedded in vertical-cavity surface-emitting laser (VCSEL) structures both gain guided and index guided. In particular, we focus in the control of the transverse modes within the VCSEL cavity. As expected in originally gain-guided VCSELs, the index guiding provided by the PC dominated the gain guiding. The single mode defined by a PC waveguide can be obtained in originally index-guided VCSELs as well as a result of depositing the oxide at the node position. It is shown that the thermal lensing effect leads to multimode generation in the VCSEL.