Temperature-insensitive quantum dot laser

A novel approach to the design of temperature insensitive lasers has been proposed. The approach, based on blocking the parasitic recombination of carriers outside QDs, offers the possibility of achieving ultrahigh temperature stability - which has been the key desired advantage of QD lasers. This can be accomplished in at least two ways by special tailoring of heterostructures that surround the QDs. The simplest way, conceptually, is to introduce potential barriers blocking the minority-carrier transport on both sides of QDs while leaving majority-carrier injection unimpeded. Suppression of the parasitic recombination outside the QDs alone leads to characteristic temperatures T₀ above 1000 K. A particularly favorable way of accomplishing this is by using resonant-tunneling injection of majority carriers. Tunneling injection offers further enhancement of T₀ owing to an inherently suppressed pumping of the nonlasing QDs and correlated occupancies of any given QD by electrons and holes