Grating-surface-emitting lasers in a ring configuration

A monolithic grating‐surface‐emitting ring laser has been fabricated and its spectral properties and far‐field radiation pattern studied. The ring laser was configured from two columns of two‐dimensional grating‐surface‐emitting diode laser arrays. The columns were optically linked at each end with total‐internal‐reflection corner turning mirrors formed by micromachining grooves in the wafer with a focused ion beam. Single longitudinal mode operation with a high degree of spatial coherence between the two columns and a narrowing of the lateral far‐field pattern were observed.