Single contact tailored gain phased array of semiconductor lasers

We demonstrate a single contact tailored gain-guided array in which the gain profile across the array is made strongly asymmetric by varying the width of the contact stripes. A proton isolated array of six (GaAl)As lasers with 5-μm separations and widths varying linearly between 3 and 8 μm had a single lobed far field 2° wide, close to the diffraction limit for a single supermode. Fabrication of this device is simple, and suited to large-scale processing techniques. We also show that in such an asymmetric gain-guided array the fundamental mode is favored over higher order modes, and that higher order modes can have single lobed far-field patterns differing only slightly from that of the fundamental.