Sung-Jae An

Polarization characteristics of photonic quantum ring laser with three-dimensional whispering gallery resonances

We report polarization characteristics of light from a photonic quantum ring (PQR) laser of three-dimensional (3D) whispering gallery modes. The 3D polarization states of light from the PQR laser were studied with a home-built solid-angle scanner capable of detecting the spatial intensity distribution in a wide range of solid angles. The analysis shows that the dominant polarization vectors of the PQR laser emitting in the surface normal direction lie always tangential to the PQR perimeter, which means there is a strong carrier-photon coupling.

Single mode photonic quantum ring laser fabricated in hyperboloid drum shape

From three dimensional whispering gallery cavities of GaAs photonic quantum ring fabricated in hyperboloid drum shape by chemically assisted ion beam etching with the central active region diameter of 0.9μm, we have observed single mode lasing near 838nm with a record low injection threshold of 300nA (Jth=47.1A∕cm2) in continuous wave operation at room temperature. This indicates that the quantum ring lasing phenomena associated with the three dimensional whispering gallery modes continue to persist, even at the submicron range overcoming the conventional two dimensional whispering gallery mode limit.

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.

Spectral analysis of a three-dimensional photonic quantum ring laser with 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-Perot 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-Perot 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 L2 and L, respectively.

Photonic quantum corral, carrier ordering, and photonic quantum dot/ring device

Abstract This study aims at firstly introducing a theoretical background of photonic quantum ring naturally formed by photonic quantum corral effect in the 3D Rayleigh–Fabry–Perot micro-cavity. This unique phenomenon is visualized as polar angle-dependent multi-chromatic emission spectra corresponding to an each lightwave with different optical paths. Also, we fabricated an H-D structure for a single PQR, i.e. single mode within a luminescent wavelength region and ultra-low threshold 16-K PQR laser array for such as free space optical interconnections.

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.

Polarization characteristics of photonic quantum ring laser

We report 3 dimensional (3D) polarization properties of the photonic quantum ring laser, measured with a home-made 3D far-field measurement setup. We observed unusual polarization characteristics, varying with polar angle in a spherical coordinate fashion.

Hole whispering gallery lasers of photonic quantum ring

We report hole-like whispering gallery semiconductor lasers from naturally formed gain-guide-assisted photonic quantum rings, with thresholds potentially reducible to micro-to-nano ampere regimes. Photonic crystal-like holes lead to practical high-density electro-pumped hole emitter arrays.