Abstract
Quantum well lasers have been extremely successful in a wide range of applications, with optical fibre communications being of particular importance. However, in spite of their success, their performance is not ideal, for example, the threshold current of semiconductor lasers is often very sensitive to temperature. This has led to the need for thermoelectric coolers and associated control electronics to stabilize the laser temperature, however, such coolers often consume more energy than the laser they are controlling and also add to the overall heat dissipation of the system. Such coolers also tend to have far less long-term reliability than the laser diode itself. There are consequently many circumstances where it would be advantageous and far cheaper to simply compensate for temperature variations by mechanisms built into the epitaxial structure of the laser chip itself. This paper focuses on a new design and demonstration of a MQW laser structure which can overcome the intrinsic temperature sensitivity of the laser.