Whispering Gallery Modes in Nanosized Dielectric Resonators with Hexagonal Cross Section

Abstract

The size dependence of whispering gallery modes in dielectric resonators with hexagonal cross section has been observed within the visible spectral range for cavity diameters comparable to the light wavelength. As a model system single, tapered, high aspect ratio zinc oxide nanoneedles were analyzed. They enable systematic investigations as a function of the resonator diameter down to the nanometer regime. A simple plane wave interference model without free parameter describes the spectral positions and the linewidths of the modes in good agreement with the experiment.

Exciton Drift in Semiconductors under Uniform Strain Gradients: Application to Bent ZnO Microwires

“…We tentatively attribute the additional peak to one of the whispering gallery modes (WGMs) that are known to exist in ZnO MWs. 9,37 As WGMs are by nature coming from the entire diameter of the wire, they do not change with excitation positions, as confirmed by our CW-CL result (Figure 1f). However, since this peak is close to the band-gap energy, the refractive index is expected to show a strong dispersion and possible strong coupling could occur, 38 which makes the simulation of the energy of the mode difficult to predict.…”

Whispering gallery modes in deformed hexagonal resonators

“…On both set-ups the linear polarization of the detected luminescence can be analyzed. 3 WGM in uniform hexagons WGM in uniform hexagonal cavities have been studied experimentally in detail in a ZnO nanoneedle for mode numbers 1-7 [17]. These results have been corroborated in Ref.…”

“…In particular hexagonal cavities ( Fig. 1) have been investigated in various material systems such as (Al,Ga)As/ GaAs [20], GaN [21], (In,Ga)N [22], ZnO [17,23,24], In 2 O 3 [25], and organic materials [26]. Stimulated emission (lasing) has been demonstrated for triangular [15,27], hexagonal [28][29][30][31][32], and dodecagonal [33] cavities.…”

“…[12], the impact of deformation away from straight facets and sharp edges has been investigated for m ¼ 3 and m ¼ 4. WGM have been experimentally studied in triangular [15], square [16], hexagonal [17,18], and dodecagonal [19] cavities. In particular hexagonal cavities ( Fig.…”

“…Taking into account the phase shift during TIR, the resonance energy condition for 6-WGM in an uniform hexagonal cavity is [13,17] …”