Resonance spectrum of a three-dimensional photonic quantum ring laser with an equilateral triangle microcavity.

We have fabricated three-dimensional (3D) photonic quantum ring lasers with an equilateral triangle microcavity. Their spectra were well explained by combining the off-normal resonance and hexagonally bounced in-plane whispering-gallery-mode condition. The angular distribution of the emission modes and their discrete wavelengths were shown to be in excellent agreement with a 3D Rayleigh Fabry-Perot model. We confirmed that the allowed modes in the equilateral triangle microcavity decrease by decreasing the length of equilateral triangle side, L, and the spectral mode spacing linearly increases with the mode index m and is inversely proportional to L2.

Current-dependent spectral blueshift in a three-dimensional photonic-quantum-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.

Spectrum of three-dimensional photonic quantum-ring microdisk cavities: comparison between theory and experiment.

The spectrum of a three-dimensional Rayleigh-Fabry-Perot microdisk cavity of a photonic quantum-ring laser is analyzed for angle-dependent emission modes. It is shown that joint consideration of the Fabry-Perot resonance condition and the whispering-gallery mode boundary condition explains the emitting angles and spectral distribution of the cavity modes well.

Extremely uniform angular distributions of the three-dimensional emission spectra of photonic quantum ring lasers.

We have observed the emission spectra of three-dimensional Rayleigh-Fabry-Perot cavity whispering-gallery modes from photonic quantum ring lasers that give rise to uniform angular mode spacing in space. The observed angular distribution (0 degrees approximately 30 degrees) of the emission modes is linear with respect to the mode number. For example, the average angular mode spacing is 0.95 degrees with a standard deviation of 0.098 degrees for a 20-microm-diameter laser, whose potential angle-resolving power is promising for angle-sensing applications in the future.