A hybrid III-V on silicon laser device includes a layer structure, with a stack of III-V semiconductor gain materials, a silicon waveguide core and a cladding structure. The semiconductor gain materials stack is along a stacking direction, which is perpendicular to a main plane of the stack. The silicon waveguide core extends along a longitudinal direction, parallel to the main plane. The cladding structure extends between said waveguide core and the stack. The device further comprises an optical coupling structure formed in the layer structure. This coupling structure is designed: 1) to allow a hybrid-mode optical coupling of radiation between the stack of III-V semiconductor gain materials and the tapered waveguide core; and 2) to favor a coupling of a fundamental transverse optical mode of said radiation over a coupling of one or more higher-order transverse optical modes of said radiation from the stack into the waveguide core.