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.