Study of p-type contact topography influence on characteristics of microdisk and microring lasers

The results are presented for injection microlasers with InAs/InGaAs self-organized quantum dot active region grown on a GaAs substrate. Lasing wavelength is around 1.26...1.28 µm. It is demonstrated that the use of ring-shaped p-contact for microdisk quantum dot lasers provides lowering the threshold current as compared to that of conventional microdisk lasers with round-shaped contact topology. Both spectral characteristics and thermal resistance are preserved, whereas the series electrical resistance slightly increases.