Hole emitter of photonic quantum ring

Abstract

We report on the observation of “hole” whispering gallery lasers from semiconductor microcavities with three dimensional optical confinement, with thresholds potentially reducible to micro- to nanoampere regimes according to a quadratic size-dependent reduction, consistent with a photonic quantum corral effect of naturally formed recombinant quantum rings. If the device size grows over a critical diameter, the quantum ring whispering gallery then begins to disappear. However, cooperative small hole laser arrays, exhibiting photonic crystal structure properties, avoid the criticality and open a possibility of constructing practical high-density electropumped emitter arrays.

Photonic Quantum Ring Laser of Whispering Cave Mode

“…When the current density is the same, the more the number of petals, say the more the area of peripheral PQR region, the more the flower PQR laser intensity. We however note that the total length of peripheral PQR curves is to be smaller than the critical length for GaAs PQRs, corresponding to the device perimeter of a critical diameter (φ= ~50 m), so that the quantum ring whispering cave mode begins to disappear (Kwon et al, 2006). The photonic quantum ring (PQR) laser is an attractive candidate for high-density "laser" displays, given the unique operating characteristics attendant on its quantum-wire-like nature, such as extremely low threshold currents and thermally stable spectra in the typical operatingtemperature range.…”

“…N 1D is the 1D transparency carrier density, τ the carrier lifetime, η the quantum efficiency, and I i stands for internal loss (Ahn et al, 1999;Kwon et al, 2006). The PQR formulae are now compared with the actual data in Fig.…”

Spatiotemporal dynamics in Rayleigh band of photonic quantum ring laser

“…We then pay attention to this region where one expects to observe this resultant optical pattern of quasi-2D standing waves in the QW W Rayleigh region. The dominant azimuthal-axis polarization (Kim et al 2007) will then give rise to a 2D strong carrier coupling responsible for the PQCE, transiently inducing the concentric PQRs for imminently recombinant carriers (Kwon et al 2006). This is the most probable reason for the observation of very low quantum-wire-like threshold currents.…”

“…In the course of lasing the 3D helical standing waves transiently induces concentric PQRs ( Fig. 1c) for imminently recombinant carriers present in the peripheral Rayleigh band (Kwon et al 2006). This PQR formation in turn results in very low quantum-wire-like threshold currents, with previously reported square-root-T dependent thermal red-shift.…”

Photonic quantum ring flower laser of whispering cave mode

“…However, high-power LEDs are bulk devices, suffering therefore from inherent heating problems, and limited to low frequencies far below the gigahertz range of conventional lasers. Alternatively, the photonic quantum ring (PQR) laser is an attractive candidate for high-density 'laser' displays, given the unique operating characteristics attendant on its quantum-wire-like nature, such as extremely low threshold currents andp T-dependent thermally stable spectra in the typical operatingtemperature range [1,2]. When vertical mesa cavities are made of l/4 Al 0.92 Ga 0.08 As/Al 0.16 Ga 0.84 As distributed Bragg reflector (DBR) structures added below and above an active region of three quantum wells (QWs) of 7 nm-thick GaAs each separated by 8 nm-thick barriers of Al 0.3 Ga 0.7 As, nearly total internal reflections (TIRs) in a three-dimensional (3D) manner can create 3D whispering cave modes (WCMs) for PQR lasers [3].…”