Coupled-stripe in-phase operation of planar native-oxide index-guided AlyGa1−yAs-GaAs-InxGa1−xAs quantum-well heterostructure laser arrays

High-performance, coupled-stripe, planar, index-guided AlyGa1−yAs-GaAs-InxGa1−xAs quantum-well heterostructure (QWH) laser arrays are fabricated by the formation of a relatively thick, current-blocking, native oxide from the high-gap AlyGa1−yAs upper confining layer between active stripes. Precise control of the thickness of the native oxide layer between emitters provides a means of varying the index step between stripes, and permits tailoring of the optical profile to produce in-phase operation. The 10-stripe coupled QWH laser arrays (∼3-μm-wide stripes on 4 μm centers) exhibit near-diffraction-limited, single-lobed, far-field patterns with low continuous (cw) thresholds (∼45 mA) and cw output powers (total external differential quantum efficiency ≳50%) of over 100 mW per uncoated facet.