Laguerre-Gaussian vortex mode generation from astigmatic semiconductor microcavity

Laguerre–Gaussian (LG) vortex mode generations are demonstrated by employing the optical injection of a higher-order transverse mode into a vertical cavity surface emitting laser. In addition to the coherent LG injection, Hermite–Gaussian (HG) injection also enable LG mode generation, where the chirality is controllable by the HG mode angle of the injection beam. The result can be well understood when we consider the astigmatic Gouy phase shifts within the microcavity. HG induced vortex generation eases the symmetrical requirements of the cavity and thus extends flexibility as regards the design and fabrication of vortex lasers.