Fig. 5. Lasing performance with different structural parameters.

a Collected lasing spectrum above threshold of a fabricated PC laser with lattice constant a = 315 nm and radius r/a = 0.27. The inset shows the magnified PL spectra of the lasing peak at 1344 nm and the resonant peak at 1277 nm with the pumping power 20 μW. b Corresponding collected intensity and linewidth as a function of input pumping powers for the emission peak at 1344 nm with lasing threshold at 1.9 μW. The error bars express standard errors deduced by fitting. c Corresponding logarithmic L–L plot of the PC laser, and the blue line was theoretically obtained results by using rate equation analyses. d, e present the top-view and cross-section view of the calculated E-field profiles for the fundamental mode (1344 nm) and the first higher order mode (1277 nm), respectively.