The application of the InGaAs/InGaP double-heterostructure laser increases the band offset between the cladding layer and the active layer more than the use of conventional InGaAsP,InP lasers. We propose InGaP lattice-mismatched liquid phase epitaxy on a GaAs substrate by the epitaxial lateral overgrowth (ELO) technique. To obtain the InGaP (lambda = 820 nm) cladding layer of the InGaAs (lambda = 1.3 mum)/InGaP DH laser, Ga liquid atomic fractions X-Ga(L) were gradually reduced from those of the lattice-matching conditions. The InGalP lattice-mismatched growth on both the GaAs(100) and (111)B substrates were successfully carried out by adopting the ELO technique. (C) 2002 Elsevier Science B.V. All rights reserved.