We report the design, growth, and fabrication of strain-balanced n-type modulation-doped InGaAlAs/InGaAs multiple quantum well laser/semiconductor optical amplifiers on InP. The quantum well contains a lattice-matched InGaAs core, a compressive-strained InGaAs padding, and a tensile-strained InGaAlAs spacer. Electroluminescence spectra show higher optical gain for the quantum well e1-hh2 transition at lambda=1460 nm than the e1-hh1 transition at lambda=1550 nm. Ridge-waveguide lasers of Fabry-Perot (FP) type and tilted-end-facet (TEF) type were fabricated. The FP laser shows a lasing peak of lambda=1514 nm at threshold. Additional lasing wavelengths at lambda=1528 and 1545 nm were observed sequentially as the injection current increased. For the TEF laser, only the emission at lambda=1511 nm was observed. These TE-polarized lasing wavelengths are consistent with the delta-like absorption peaks in photocurrent spectra. The lasing performance is attributed to optical transitions within quantum dots/wires which are formed by the strain-field profile and alloy segregation/migration. (C) 2008 American Vacuum Society.