Photonic Quantum Ring Research Articles

Evanescent and propagating wave characteristics of the photonic quantum ring laser

We present the wave propagation characteristics of photonic quantum ring lasers with clear evidence of the evanescence-propagation crossover behavior. The data obtained from the fiber probe measurements of 15–36 μm disk size lasers show that the Rayleigh’s whispering gallery modes always give rise to the propagation mode, with the crossover ranges of 55–80 μm. The three-dimensional but chiral and broken z-axis symmetry nature of the photonic quantum ring cavity appears to guarantee such a crossover to the propagation in general.

Fabrication of photonic quantum ring laser using chemically assisted ion beam etching

This article presents an etching process to fabricate a high-quality vertical facet for the photonic quantum ring (PQR) laser. The presented process uses the chemically assisted ion beam etching (CAIBE) method with a gas mixture of Ar:Cl2:BCl3=5:2:3 sccm, and uses a single-layer photoresist etch mask to reduce the process complexity of etching GaAs/AlGaAs structures for the PQR laser. The angle θ between the incident beam and the normal direction of the substrate has been adjusted to achieve a high-quality vertical facet. Distortions on the mask pattern are not transferred to the etched side wall for θ⩾25°, and a vertical facet is obtained at θ∼25°. The fabricated PQR lasers with the CAIBE process in this article show a sharp linewidth of ∼0.06 nm.