Dependence of InGaAs/InP multiquantum well laser characteristics on the degree of substrate misorientation

The threshold current density, internal quantum efficiency, internal loss, and emission wavelength of InGaAsP/InP multiquantum well lasers, grown by atmospheric pressure metalorganic chemical vapor deposition, were measured as a function of substrate orientation on and away from the (001) towards the nearest [011] and [111]A. The laser parameters are optimized for (001) oriented substrates. Substrate misorientations of more than 3° in either direction yield lasers with increased threshold current density and lower internal quantum efficiency. The internal loss increases and the surface morphology becomes visually poorer for substrate misorientations of 6°. The laser emission shifts to longer wavelength with increasing misorientation.