A room temperature electrically pumped 1.3-µm InAs quantum dot laser monolithically grown on silicon substrates

Abstract

We present a room-temperature 1.3-µm InAs/GaAs quantum dot laser monolithically grown on Si(100). The threshold current at 20°C was 725A/cm 2 and the emission wavelength was 1.302µm. The laser was operated in pulsed mode. The growth was enabled via the optimisation of the temperature of the initial nucleation layer of GaAs. IntroductionA laser on silicon is highly desirable for silicon photonics. In addition, this area along with silicon based modulators has been heavily researched [1][2][3][4][5]. However there are two main issues preventing the realisation of an all silicon laser, the indirect bandgap of Si and two photon absorption. An alternative is to monolithically grow conventional III-V compounds on Si [6,7]. There are still many challenges to solve using this technique. Firstly the large lattice mismatch between III-V compounds and Si which can lead to high threading dislocation (TD) densities and secondly the polar/non-polar characteristic of III-V/IV system leads to the formation of antiphase domains (APD) which have a significant effect on the threshold current, J th [8]. In conventional III/VSi quantum well (QW) lasers any TD or APD in the active layer would lead to the formation of a non-radiative centre, and hence significantly increase J th [9].