Current-dependent spectral blueshift in a three-dimensional photonicquantum-ring laser

The emission spectra of photonic-quantum-ring lasers can be explained by a three-dimensional Rayleigh-Fabry-Perot cavity resonance model. The proposed model for the emission spectral peaks fits well with the observed blueshift of the emission spectrum envelope as a function of the view angle. Furthermore, we observe that the emission spectra with the high-order mode index showed blueshift behaviors as functions of the injection current, whereas those with the low-order mode index showed redshift behaviors. These phenomena might result in lowering the effective refractive index by the carrier inhomogeneity in the active disk.