The dependence of threshold current density and lateral-index difference for transverse guiding in a 1.55-µm InGaAsP/InP ridge-waveguide laser on the number of cladding layers, their thicknesses, and their compositions is presented. It is found that two cladding layers of intermediate band-gap InGaAsP (λg = 1.2–1.3 µm) are desirable to reduce the threshold current density and to reduce its sensitivity to layer-thickness variations. The use of active- and cladding-layer thicknesses between 0.1 and 0.15 µm minimizes the threshold current density and its sensitivity to layer-thickness variations. This regime of layer thicknesses results in relatively strong lateral-index guiding (Δneff ≈ 0.06) in the 1.55-µm ridge-waveguide laser structure.
© 1984 Optical Society of America
J. E. Bowers and D. P. Wilt, "Optimum design of 1.55-µm double heterostructures and ridge-waveguide lasers," Opt. Lett. 9, 330-332 (1984)