Two methods were studied to improve the optical quality of InAs quantum dot nanostructures grown in lattice-matched InAlGaAs/InP double heterostructures of a center wavelength around 1.55 mu m. By either inserting InAlAs/InGaAs superlattices between the InAlGaAs waveguide and the upper InAlAs cladding layer, or depositing a ten sile-strained InGaAs strain-balance layer after the quantum dot formation, the optical quality of the quantum dot samples is greatly improved and a strong room-temperature photoluminescence is observed. The InGaAs strain-balance layer can be used to reduce the overall strain of the heterostructure, which makes it possible to stack a large number of quantum dot layers to improve the uniformity of the dot size distribution and increase the optical gain volume for high performance photonic device applications. (c) 2005 American Vacuum Society.