High-performance index-guided phase-locked semiconductor laser arrays

Using strongly coupled index-guided ridge-waveguide structures and tailoring the gain distribution to the fundamental eigenmode intensity distribution in a five-element coupled laser array, we greatly improve the performance over previously reported results. A stable single-lobe far-field pattern has been observed up to nearly three times threshold. This result is achieved by nonuniform pumping, which tends to excite the fundamental array eigenmode only by preventing spatial hole burning, which causes the excitation of higher-order modes.