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Compact and efficient light sources are essential for integrated photonic circuits, yet their direct integration with silicon-based platforms remains challenging due to the inefficient light emission of silicon. III–V semiconductor nanowires offer a promising route towards nanoscale light sources, combining a small footprint and efficient strain relaxation with the direct band gap required for optical gain and lasing.
In this work, InGaAs/InAlAs core–shell nanowires are investigated as individual Fabry–Pérot laser cavities for long-wavelength emission relevant to silicon photonics. Nanowire samples with different nominal indium contents were studied using a combination of optical simulations, growth optimization, structural characterization, and single-nanowire μ-photoluminescence spectroscopy. The simulations were used to guide the design of nanowire geometries supporting guided-mode lasing, while structural characterization provided insight into the morphology of the grown nanowire ensembles.
Photoluminescence measurements confirmed a systematic red shift of the emission with increasing indium content, demonstrating the tunability of the InGaAs/InAlAs material system. Power-dependent measurements on individual lying nanowires revealed a clear transition from spontaneous emission to stimulated emission and lasing, with spectral features consistent with Fabry–Pérot cavity modes. Temperature-dependent measurements further demonstrated lasing from single InGaAs nanowires up to room temperature.
In addition, mode-profile simulations were performed in the experimentally relevant lying-nanowire geometry to support the interpretation of future optical measurements. Overall, these results highlight InGaAs/InAlAs core–shell nanowires as a promising platform for long-wavelength single-nanowire lasers and provide design guidelines for their future integration into photonic circuits.
