We have investigated atomic level interface structures and characteristics of GaInP/GaAs/GaInP double heterostructures grown by low-pressure organometallic vapor phase epitaxy. In photoluminescence (PL) measurements, interface-related emission was clearly observed in the sample grown at 580 degreesC, while it disappeared in the sample grown at 540 degreesC. X-ray crystal truncation rod scattering measurement revealed that In atoms distribute significantly in the GaAs layer (similar to12 ML) when the GaAs-on-GaInP interface is grown at 580 degreesC and the distribution is highly suppressed when grown at 540 degreesC. By insertion of a thin GaInP layer grown at 540 degreesC to the GaAs-on-GaInP interface in GaInP/GaAs/GaInP laser diodes, threshold current densities were much lower and more uniform than those of the diodes with GaAs-on-GaInP interfaces grown at 580 degreesC. (C) 2004 Published by Elsevier B.V.