Phase-locked shallow mesa graded barrier quantum well laser arrays

Graded barrier quantum well heterostructures have been grown by metalorganic chemical vapor deposition and processed into real index-guided shallow mesa laser arrays. Single-stripe devices have threshold currents as low as 14 mA (533 μm length) and ten-element arrays have threshold currents as low as 9 mA per stripe with 52% differential quantum efficiency. These arrays operate phase locked with sharp double-lobed far-field patterns up to 1.75 times threshold current.