Fig. 1. Epitaxial structure of the QD laser on silicon.

Fig. 2. Optical injection locking setup used for the four-wave mixing experiments.

Fig. 3. Optical spectra from a four-wave mixing experiment for (a) undoped QD laser with upconversion frequency detuning of −114  GHz (probe–drive mode number difference Δm=3); (b) p-doped QD laser with upconversion frequency detuning of −89  GHz (probe–drive mode number difference Δm=3) and QW laser with upconversion frequency detuning of −110  GHz (probe–drive mode number difference Δm=1). The different colored lines indicate signal power increases with increasing probe power.

Fig. 4. Conversion efficiency of four-wave mixing for p-doped QD, undoped QD, and QW lasers as a function of probe–drive frequency detuning.

Fig. 5. Signal–drive ratio ηsd as a function of probe–drive ratio ηpd for p-doped QD, undoped QD, and QW lasers. The lasers are biased at twice threshold current. The data points are from the experiment with probe–drive injection frequency detuning Δ and probe–drive mode number difference Δm as indicated. The dashed curves are calculated from multimode laser theory indicating the corresponding FWM coefficient.