3-DIMENSIONAL ARRAYS OF SELF-ORDERED QUANTUM DOTS FOR LASER APPLICATIONS

Semiconductor heterostructures with quantum dots (QDs) are experimenta lly proved to exhibit properties expected for zero-dimensional systems , e.g. ultrasharp luminescence lines up to high temperatures, massivel y increased exciton oscillator strength per unit Volume and temperatur e insensitivity of the radiative lifetime. When applied to the injecti on lasers these advantages help to increase strongly material gain, di fferential gain, to improve temperature stability of the threshold cur rent and to suppress chirp. Threshold current densities as low as 60 A /cm(2) at 300 K are obtained. Formation of QDs with properties satisfy ing device requirements on QD size, shape, uniformity and density beca me possible by utilizing self-ordering phenomena on crystal surfaces. (C) 1997 Elsevier Science Ltd.