Spectral analysis of a three-dimensional photonic quantum ring laserwith a square microcavity

Three-dimensional photonic quantum ring lasers with a square microcavity were fabricated and their spectra were explained by combining two conditions: the off-normal Fabry-Pérot resonance and quadruple-bounced whispering-gallery mode. The angular distribution of the emission modes and their discrete wavelengths were in excellent agreement with a three-dimensional Rayleigh-Fabry-Pérot model. The three-dimensional model also showed that the slope of the spectral mode spacing and the value of the angular mode spacing as a function of the length of a square side L are inversely proportional to L 2 and L , respectively.