| abstract |
A method for achieving large localized bandgap energy differences at the wafer-level scale, with fine bandgap control, through a combination of regrowth and quantum well intermixing processes. The technique allows fabrication of a photonic integrated circuit on a wafer, wherein epitaxial layers of different composition are formed on separate regions to optimise the associated energy bandgap at a different centre wavelength. Quantum well intermixing of those parts of the structure containing quantum wells allows localised fine tuning of the bandgap, either to correct for inaccuracies during deposition or growth, or intentionally to detune the bandgap to achieve a certain functionality such as greater transparency or responsivity. |