Non-linear excitation and correlation studies of single InGaN quantum dots

The exact mechanism for non‐linear sub‐bandgap excitation of single InGaN quantum dots (QDs) has been investigated using interferometric autocorrelation techniques based around a near‐infrared (NIR) excitation laser. We identify unambiguously the heavily favoured two‐photon absorption (TPA) as being crucial in the observed background reduction for such Nitride structures and compare systematically the relative merits of both the linear (blue) and non‐linear (NIR) excitation regimes on several apertures of a masked sample. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)