InAs/InP quantum dots emitting in the 1.55μm wavelength region by inserting ultrathin GaAs and GaP interlayers

We present an effective method to tune the emission wavelength of InAs/InP(1 0 0) quantum dots (QDs) in the 1.55μm wavelength region. The InAs QDs are embedded in lattice-matched GaInAsP which is the waveguide core material in InP-based photonic devices. By inserting ultrathin GaAs (0.3-2.5 monolayers (MLs)) or GaP (0.3-1.1 MLs) layers between the QDs and the GaInAsP buffer, continuous wavelength tuning from above 1.60μm to below 1.5μm at room temperature is demonstrated by varying solely one growth parameter, i.e., the interlayer thickness. The thin GaAs and GaP interlayers play an important role in suppressing As/P exchange and consuming surface-segregated In, leading to drastic reduction of the emission wavelength of the InAs QDs.