Anisotropic Radiation in Heterostructured Emitter in a Cavity Nanowire

Tailorable synthesis of axially heterostructured epitaxial nanowires (NWs) with a proper choice of materials allows for the fabrication of novel photonic devices, such as a nanoemitter in the resonant cavity. An example of the structure is a GaP nanowire with ternary GaPAs insertions in the form of nano-sized discs studied in this work. With the use of the micro-photoluminescence technique and numerical calculations, we experimentally and theoretically study photoluminescence emission in individual heterostructured NWs. Due to the high refractive index and near-zero absorption through the emission band, the photoluminescence signal tends to couple into the nanowire cavity acting as a Fabry-Perot resonator, while weak radiation propagating perpendicular to the nanowire axis is registered in the vicinity of each nano-sized disc. Thus, within the heterostructured nanowire, both amplitude and spectrally anisotropic photoluminescent signals can be achieved. Numerical modeling of the nanowire with insertions emitting in infrared demonstrates a decay in the emission directivity and simultaneous rise of the emitters coupling with an increase in the wavelength. The emergence of modulated and non-modulated radiation is discussed, and possible nanophotonic applications are considered.

Automated summary

Tailorable synthesis of axially heterostructured epitaxial nanowires allows for the fabrication of novel photonic devices. In this study, the photoluminescence emission in individual heterostructured nanowires was experimentally and theoretically studied. It was found that the high refractive index and near-zero absorption through the emission band enable the coupling of photoluminescence signal into the nanowire cavity, while weak radiation is registered in the vicinity of each nano-sized disc.