Single-mode vertical-cavity surface-emitting laser with ring-shaped light-emitting aperture

In this letter, we demonstrate a single-mode vertical-cavity surface-emitting laser (VCSEL) with a ring-shaped light-emitting aperture, which is realized by the Zn diffusion technique, at a wavelength of 850 nm. Relative to the control VCSEL with an ordinary circular aperture and the same geometry and size, the demonstrated device can suppress the higher-order transverse mode more effectively without affecting the threshold current and output power. Compared with typical reported single-mode VCSELs, a larger light-emitting aperture and current-confined area with a smaller divergence angle of the output beam, and lower differential resistance are achieved with the present structure.