The influence of InAs growth rate and the group V-III beam equivalent pressure ratio on the optical and structural properties of InAs quantum dots in constant and graded composition (In,Ga)As quantum wells is investigated. Optimized growth conditions are found for both structures. It is suggested that the "dots-in-a-graded-well" structure might serve as a better active medium than the "dots-in-a-well" structure. Both structures are engineered to emit at the important telecommunication wavelength of 1.3 mum. (C) 2003 Elsevier Science B.V. All rights reserved.