In-phase Evanescent Coupled Implant Defined Vertical Cavity Laser Arrays

Arrays of vertical cavity surface emitting lasers (VCSELs) have been studied extensively for coherent coupling between lasers. In this work, we show that proton implantation may be used to define individual elements in the coupled array. This approach adds no fabrication complexity to that of a conventional implant VCSEL. Because the implant provides electrical confinement without adding optical loss, the lasers tend to lock in-phase. A near-field image and a far-field pattern for a 2times1 array are shown at an injection current of 4.3 mA. As injection current is increased to these implant-defined arrays, higher-order transverse modes turn on, which limits the single-mode output power. Ongoing efforts are to suppress these higher order modes and thus allow these evanescently coupled arrays to operate in-phase with higher injection current