Linear tailored gain broad area semiconductor lasers

Tailored gain semiconductor lasers capable of high-power operation with single-lobed, nearly diffraction limited beamwidths only a few degrees wide have been demonstrated in proton implanted chirped arrays and "halftone" broad area lasers. We analyze lasers with a linear gain gradient, and obtain analytic approximations for their unsaturated optical eigenmodes. Unlike a uniform array, the fundamental mode of a linear tailored gain laser is the lasing mode at threshold. Mode discrimination may be controlled by varying the spatial gain gradient. All modes of asymmetric tailored gain waveguides have single-lobed far-field patterns offset from 0°. Finally, we utilize tailored gain broad area lasers to make a measurement of the anti-guiding parameter, and find
b = 2.5 \pm 0.5
, in agreement with previous results.