Holistic Nanowire Laser Characterization as a Route to Optimal Design

Nanowire lasers are sought for near‐field and on‐chip photonic applications as they provide integrable, coherent, and monochromatic radiation: the functional performance (threshold and wavelength) is dependent on both the opto‐electronic and crystallographic properties of each nanowire. However, scalable bottom‐up manufacturing techniques often suffer from inter‐nanowire variation, leading to differences in yield and performance between individual nanowires. Establishing the relationship between manufacturing controls, geometric and material properties, and the lasing performance is a crucial step toward optimisation; however, this is challenging to achieve due to the interdependance of such properties. Here, a high‐throughput correlative approach is presented to characterise over 5000 individual GaAsP/GaAs multiple quantum well nanowire lasers. Fitting the spontaneous emission provides the threshold carrier density, while coherence length measurements determine the end‐facet reflectivity. The performance is intrinsically related to the width of a single quantum well due to quantum confinement and bandfilling effects. Unexpectedly, there is no strong relationship between the properties of the lasing cavity and the threshold: instead the threshold is negatively correlated with the non‐radiative recombination lifetime of the carriers. This approach therefore provides an optimisation strategy that is not accessible through small‐scale studies. High‐throughput imaging and optical characterisation techniques are applied to more than 5000 individual nanowire lasers, which holistically characterise the cavity, gain, and performance of the nanowires. By studying correlations within this dataset, it was established that the gain, not the cavity, limits the performance.