Supersymmetric microring laser arrays

Abstract

Coherent combination of emission power from an array of coupled semiconductor\nlasers operating on the same chip is of fundamental and technological\nimportance. In general, the nonlinear competition among the array supermodes\ncan entail incoherence and spectral broadening, leading to spatiotemporally\nunstable and multimode emission pattern and thus poor beam quality. Here, by\nharnessing notions from supersymmetric (SUSY) quantum mechanics, we report that\nthe strategic coupling between a class III-V semiconductor microring laser\narray with its dissipative superpartner can be used to limit the number of\nsupermodes available for laser actions to one. We introduce a novel approach\nbased on second-order SUSY transformation in order to drastically simplify the\nsuperpartner array engineering. Compared to a conventional laser array, which\nhas multimode spectrum, a SUSY laser array is observed to be capable of\noperating in a single (transverse) supermode. Enhancement of the peak output\nintensity of the SUSY laser array has been demonstrated with high-efficiency\nand lower lasing threshold, compared with a single laser and a conventional\nlaser array. Our experimental findings pave the way towards broad-area and\nhigh-power light generation in a scalable and stable fashion.\n