Realization of large subband separation and high power light output in GaAs/AlGaAs two-dimensional quantum well wire laser arrays

Abstract

Incorporating lower-dimensional structures such as quantum well wires (QWWs) and dots into semiconductor laser structures is expected to result in improved laser performance1. The technique of fabrication QWWs on nonplanar substrates by metal-organic chemical vapor deposition (MOCVD) is much potential due to formation of defect-free interfaces entirely during the epitaxial growth process2. With this approach, enhanced optical gain3,4 and ultralow threshold current2,5 have been demonstrated in QWW lasers. However, large QWW subband separation greater than thermal energy kBT at room temperature (~25meV) is still desirable, which should be realized by reducing wire sizes. The small wire volume, however, is disadvantageous for achieving high power light output of QWW lasers for some practical applications.