Polariton Lasing of Multiple-Layered InGaN/GaN/AlGaN Axial Heterostructure Nanorods for Tunable Nanolasers

Abstract

Polariton lasing of nanorods is investigated in a multiple-layered axial heterostructure to realize tunable features of lasing, such as the threshold, wavelength, and mode spacing. In a cylindrical nanorod with the configuration of GaN/AlGaN/InGaN/AlGaN/GaN prepared using a top–down approach, the excitonic emission of composite materials indicates the successful formation of the heterostructure, while the distinctive lasing of individual composites suggests controllable properties in the heterostructure. The optical confinement effects enhance the development of an exciton–polariton, leading to the characteristic refractive index in each layer due to the energy-dependent dispersion. The unique Fabry–Pérot modes of lasing propose manageable mode spacing by varying the polaritonic effects and composite materials, even without a change in the length. In addition, the feature of a polariton improves the reflectivity of end facets, which is further enhanced by the modification with silver to lower the lasing threshold. Polariton lasing in the multiple-layered axial heterostructure nanorod is observed for the first time, demonstrating the possibility of controlling the characteristics of lasing by the modulation of the gain volume, layer sequence, and end facet. Polariton nanolasers are expected to enhance the efficiency of nanoscale devices with tunable wavelength, optical gain, and mode spacing.