Figure 4: Optical characterization of a nanoisland laser.

(a) Photoluminescence spectrum of the nanobeam as a function of absorbed power. The inset describes the polarization of the lasing mode. (b) Output power of the lasing mode is plotted in logarithmic scale. The inset shows the same data in linear scale with linewidth as a function of absorbed power, which proves the existence of the threshold around 210 nW.