Dual-mode Vertex-deformed Square Microcavity Lasers

Vertex-deformed square microcavity lasers with a connected output waveguide are proposed to support dual-mode lasing. Two opposite circular vertices are introduced to enlarge the mode interval between the fundamental and the first order transverse modes, and pure dual-mode lasing is realized due to the suppression of high-order transverse modes. For a deformed 30-μm-side-length square microcavity laser with a 1.5-μm-wide waveguide, dual-mode lasing is verified with intervals from 0.46 to 1.60 nm by controlling the circular vertices radius. The autocorrelation traces prove that the proposed microlasers emit dual modes synchronously and have potential applications in sub-THz wave generation.