ABSTRACT
Low-dimensional semiconductor heterostructures have been predicted to provide vast im provements particularly to semiconductor laser diodes [1]. Most prominently, zero dimensional quantum dots are expected to provide ultra-low, temperature insensitive, threshold currents and ultrafast modulation response. Successful realization of quantum dot lasers has been possible through the use of self-organized quantum dots [2] in the InAs/GaAs [3] and InP/GalnP [4] material systems. Quantum dot lasers made from In(Ga)As/GaAs structures exhibit record-low threshold current densities of 26 A/cm2 [5], are capable of high-power operation up to 3 W [6], and may allow access to telecommunications wavelengths using GaAs-based materials [7]. In the visible wavelength range, quantum dot lasers based on InP/GalnP materials have only recently been pushed towards room tempera ture operation [8,9].
